D defs.my
Entry 3 senses Webster, 1913

Loser

/lo͞oz'-ẽr/ · Los·er · IPA /luzɚ/
01 n. One who loses; as, the loser pays for a round of beer.
  1. 1.
    One who loses; as, the loser pays for a round of beer.
  2. 2.
    A person who is habitually unsuccessful at some endeavor, such as employment or personal relationships.[slang]
  3. 3.
    A plan or strategy unlikely to succeed.[slang]