How many letters does the top answer for “to ascend, as by means of the hands and feet, or laboriously or slowly; to mount.” have?

The most common answer is climb (5 letters).

Crossword clue: to ascend, as by means of the hands and feet, or laboriously or slowly; to mount.

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

climb 5 letters web-def

go upward with gradual or continuous progress