How many letters does the top answer for “the side or slope of a mountain” have?

The most common answer is mountainside (12 letters).

Crossword clue: the side or slope of a mountain

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

mountainside 12 letters wn-def

the side or slope of a mountain

versant 7 letters wn-def

the side or slope of a mountain

the side or slope of a hill 50% similar → hillside