■ noun
1》 a playing card with a single spot on it, the highest card in its suit in most games.
2》 informal a person who excels at a particular activity.
3》 Tennis a service that an opponent is unable to return.
4》 Golf a hole in one.
■ adjective informal very good.
■ verb informal
1》 (in tennis) serve an ~ against.
2》 Golf score an ~ on (a hole).
3》 N. Amer. achieve high marks in (a test or exam).
Phrases
~ up one's sleeve (or N. Amer. in the hole ) something effective kept in reserve.
hold all the ~s have all the advantages.
within an ~ of very close to.
Origin
ME (denoting the ‘one’ on dice): via OFr. from L. as 'unity, a unit'.