abyss

Từ điển WordNet v3.1 - WordNet Dictionary

noun

a bottomless gulf or pit;
any unfathomable (or apparently unfathomable) cavity or chasm or void extending below (often used figuratively) (Freq. 3)
• Syn:
abysm
• Derivationally related forms:
abysmal (for: abysm), abyssal
• Hypernyms:
chasm