How many letters does the top answer for “in opposition to a proposition, opinion, etc.” have?

The most common answer is con (3 letters).

Crossword clue: in opposition to a proposition, opinion, etc.

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

con 3 letters wn-def

an argument opposed to a proposal

in favor of a proposition, opinion, etc. 60% similar → pro