Tra từ signal - Từ điển Oxford Advanced Learner 8th

sig·nal [signal signals signalled signaled signalling signaling] noun, verb, adjective BrE [ˈsɪɡnəl] NAmE [ˈsɪɡnəl]
noun
1. a movement or sound that you make to give sb information, instructions, a warning, etc.
Syn: ↑sign
•a danger/warning/distress, etc. signal
• At an agreed signal they left the room.
• The siren was a signal for everyone to leave the building.
•When I give the signal, run!
• (NAmE)All I get is a busy signal when I dial his number (= his phone is being used).
•hand signals (= movements that ↑cyclists and drivers make with their hands to tell other people that they are going to stop, turn, etc.)
see also ↑turn signal
2. an event, an action, a fact, etc. that shows that sth exists or is likely to happen
Syn: ↑indication
• The rise in inflation is a clear signal that the government's policies are not working.
• Chest pains can be a warning signal of heart problems.
•Reducing prison sentences would send the wrong signals to criminals.
3. a piece of equipment that uses different coloured lights to tell drivers to go slower, stop, etc, used especially on railways/railroads and roads
•traffic signals
•a stop signal
• Delays are occurring as a result of signal failure on the northbound line.
4. a series of electrical waves that carry sounds, pictures or messages, for example to a radio, television or mobile/cell phone
•TV signals
•a high-frequency signal
•a radar signal
•to detect/pick up signals
•to emit a signal
• I couldn't get a signal on my cell phone.
• The satellite is used for transmitting signals around the world.

Word Origin:
v. and n. late Middle English Old French medieval Latin signale late Latin signalis Latin signum ‘mark, token’ adj. early 17th cent. French signalé Italian segnalato ‘distinguished, made illustrious’ segnale ‘a signal’

Thesaurus:
signal noun C
•When I give the signal, run!
sign • • cue •
a signal/sign/cue for sb/sth
give sb a signal/sign/cue
wait for/miss a/your signal/sign/cue
understand/misunderstand a signal/sign

Synonyms:
sign
indication • symptom • symbol • indicator • signal
These are all words for an event, action or fact that shows that sth exists, is happening or may happen in the future.
sign • an event, action or fact that shows that sth exists, is happening or may happen in the future: ▪ Headaches may be a sign of stress.
indication • (rather formal) a remark or sign that shows that sth is happening or what sb is thinking or feeling: ▪ They gave no ▪ indication as to ▪ how the work should be done.
sign or indication?
An indication often comes in the form of sth that sb says; a sign is usually sth that happens or sth that sb does.
symptom • a change in your body or mind that shows that you are not healthy; a sign that sth exists, especially sth bad: ▪ Symptoms include a sore throat. ◇ ▪ The rise in inflation was just one symptom of the poor state of the economy.
symbol • a person, object or event that represents a more general quality or situation: ▪ The dove is a universal symbol of peace.
indicator • (rather formal) a sign that shows you what sth is like or how a situation is changing: ▪ the economic indicators
signal • an event, action or fact that shows that sth exists, is happening or may happen in the future: ▪ Chest pains can be a warning signal of heart problems.
sign or signal?
Signal is often used to talk about an event, action or fact that suggests to sb that they should do sth. Sign is not usually used in this way: Reducing prison sentences would send the wrong signs to criminals.
a(n) sign/indication/symptom/symbol/indicator/signal of sth
a(n) sign/indication/symptom/indicator/signal that…
a clear sign/indication/symptom/symbol/indicator/signal
an obvious sign/indication/symptom/symbol/indicator
an early sign/indication/symptom/indicator/signal
an outward sign/indication/symbol
to give a(n) sign/indication/signal

Example Bank:
•A strong buy signal was issued to traders.
•All I get is a busy signal when I dial his number.
•At a pre-arranged signal, everyone started cheering.
•He had arranged a signal for the band to begin.
•Interviewers quickly learn to pick up non-verbal signals.
•It is possible to jam GPS signals in battle.
•Laughing when you should be crying sends out the wrong signals to people.
•She made a signal for the car to stop.
•The brain interprets the signals from the retina as light.
•The digital signal travels down wires to the server.
•The insect's bright colours act as warning signals to its predators.
•The insect's yellow spots act as a warning signal to its predators.
•The nerves carry these signals to the brain.
•The remark was interpreted as a signal that their government was ready to return to the peace talks.
•The signal is scrambled into code before it is sent.
•The traffic signals were on red.
•This equipment can detect very low frequency signals.
•Try to read the signals coming from the patient.
•Wait for the signal from the leader of your group.
•When I give the signal, run!
•a faint signal from the satellite
•the signals that can indicate danger
•The rise in inflation is a clear signal that the government's policies are not working.
•a danger/distress signal
•hand signals
Derived Word: ↑signally

verb (-ll-, US -l-)
1. intransitive, transitive to make a movement or sound to give sb a message, an order, etc
• Don't fire until I signal.
• Did you signal before you turned right?
•~ (to sb) (for sth) He signalled to the waiter for the bill.
•~ to/for sb to do sth He signalled to us to join him.
•The patrolman signalled for her to stop.
•~ sb to do sth She signalled him to follow.
•~ sth The referee signalled a foul.
•~ (that)… She signalled (that) it was time to leave.
•~ which, what, etc… You must signal which way you are going to turn.
2. transitive ~ sth to be a sign that sth exists or is likely to happen
Syn: ↑indicate
•This announcement signalled a clear change of policy.
•The scandal surely signals the end of his political career.
3. transitive to do sth to make your feelings or opinions known
•~ sth He signalled his discontent by refusing to vote.
•~ (that)… She has signalled (that) she is willing to stand as a candidate.
Verb forms:

Word Origin:
v. and n. late Middle English Old French medieval Latin signale late Latin signalis Latin signum ‘mark, token’ adj. early 17th cent. French signalé Italian segnalato ‘distinguished, made illustrious’ segnale ‘a signal’

Thesaurus:
signal verb I, T
•Don't fire until I signal.
nod • • wave • • beckon • |written gesture •
signal/nod/wave/beckon/gesture to sb
signal/nod/gesture for sb to do sth
signal/gesture that sb should do sth/it is time to do sth, etc.

Example Bank:
•A change of mind in one instance does not necessarily signal a change in overall policy.
•A fall in demand does not necessarily signal the death of the industry.
•He raised his hand and signalled for the waiter.
•I saw her signal frantically to us.
•She signalled frantically to us.
•She signalled to the bus driver to stop.
•These changes clearly signal the end of the welfare state as we know it.
•These events appeared to signal the end of an era.
•This address was meant to signal a change in policy.
•Always make sure you signal before you start to turn.
•Don't fire until I signal.
•Joe signalled to us to join him.
•Many animals use their tails to signal.
•She signalled that it was time to leave.
•The referee seemed to be signalling a foul.
•When I'm ready I'll signal with a flashlight.

adjective only before noun (formal)
important and noticeable
•a signal honour
•a signal failure of leadership

Word Origin:
v. and n. late Middle English Old French medieval Latin signale late Latin signalis Latin signum ‘mark, token’ adj. early 17th cent. French signalé Italian segnalato ‘distinguished, made illustrious’ segnale ‘a signal’