How many letters does the top answer for “varying slightly from a perfectly spherical shape” have?

The most common answer is aspheric (8 letters).

Crossword clue: varying slightly from a perfectly spherical shape

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

aspheric 8 letters wn-def

varying slightly from a perfectly spherical shape

aspherical 10 letters wn-def

varying slightly from a perfectly spherical shape