How many letters does the top answer for “touch or stroke lightly” have?

The most common answer is tickle (6 letters).

Crossword clue: touch or stroke lightly

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

tickle 6 letters wn-def

the act of tickling

a light touch or stroke 50% similar → dab, pat

to touch lightly. coles. 50% similar → attinge