How many letters does the top answer for “another word for breathing” have?

The most common answer is eupneic (7 letters).

Crossword clue: another word for breathing

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

eupneic 7 letters gen-syn

passing or able to pass air in and out of the lungs normally; sometimes used in combination

eupnoeic 8 letters gen-syn

passing or able to pass air in and out of the lungs normally; sometimes used in combination

another word for about 50% similar → approximately, roughly, some

another word for terms 50% similar → footing

another word for under 50% similar → nether

another word for word 50% similar → phrase