How many letters does the top answer for “a hard blow. halliwell.” have?

The most common answer is siserara (8 letters).

Crossword clue: a hard blow. halliwell.

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

siserara 8 letters web-def

A hard blow. [Prov. Eng.] Halliwell.

siserary 8 letters web-def

A hard blow. [Prov. Eng.] Halliwell.

blow hard and loudly 50% similar → chuff, huff

blow or breathe hard on or into 50% similar → insufflate

deliver a hard blow to 50% similar → smack, thwack