singleton

Từ điển WordNet v3.1 - WordNet Dictionary

noun

1. a single object (as distinguished from a pair)
• Hypernyms:
one, 1, I, ace, single, unity
• Hyponyms:
mate, fellow
2. a set containing a single member
• Hypernyms:
set
3. the playing card that is the only card in a suit held in a bridge hand as initially dealt
• Hypernyms:
playing card