How many letters does the top answer for “an acrobat who performs on a tightrope or slack rope” have?

The most common answer is funambulist (11 letters).

Crossword clue: an acrobat who performs on a tightrope or slack rope

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

funambulist 11 letters wn-def

an acrobat who performs on a tightrope or slack rope

walking on a tightrope or slack rope 50% similar → funambulism