coupon

Từ điển WordNet v3.1 - WordNet Dictionary

noun

1. a negotiable certificate that can be detached and redeemed as needed (Freq. 1)
• Syn:
voucher
• Hypernyms:
commercial document, commercial instrument
• Hyponyms:
book token, meal ticket, luncheon voucher, twofer
2. a test sample of some substance (Freq. 1)
• Hypernyms:
sample