bachelor

Concise Oxford English Dictionary © 2008 Oxford University Press:
bachelor/ˈbatʃələ(r)/

▶noun

• 1 a man who is not and has never been married.

  ■ Zoology a male bird or mammal prevented from breeding by a dominant male.

• 2 a person who holds a first degree from a university or other academic institution (only in titles or set expressions).

• 3 historical a young knight serving under another's banner.

– derivatives
bachelorhood noun.

– origin ME: from OFr. bacheler ‘a young man aspiring to knighthood’.