How many letters does the top answer for “omission or suppression of parts of words or sentences” have?

The most common answer is eclipsis (8 letters).

Crossword clue: omission or suppression of parts of words or sentences

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

eclipsis 8 letters wn-def

omission or suppression of parts of words or sentences

ellipsis 8 letters wn-def

omission or suppression of parts of words or sentences