penknife

Từ điển Oxford Advanced Learner 8th

pen·knife [penknife penknives] BrE [ˈpennaɪf] NAmE [ˈpennaɪf] noun (pl. pen·knivesBrE [ˈpennaɪvz] ; NAmE [ˈpennaɪvz] ) (also pock·et·knife especially in NAmE)
a small knife with one or more blades that fold down into the handle
See also: ↑pocketknife

Example Bank:
•He pulled the penknife out of his pocket and opened it.