How many letters does the top answer for “an unsuccessful ending to a struggle or contest” have?

The most common answer is defeat (6 letters).

Crossword clue: an unsuccessful ending to a struggle or contest

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

defeat 6 letters wn-def

win a victory over

licking 7 letters wn-def

an unsuccessful ending to a struggle or contest

a successful ending of a struggle or contest 60% similar → triumph, victory