How many letters does the top answer for “deliver a hard blow to” have?

The most common answer is smack (5 letters).

Crossword clue: deliver a hard blow to

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

smack 5 letters wn-def

deliver a hard blow to

thwack 6 letters wn-def

a hard blow with a flat object

deliver a blow to 67% similar → belt

a hard blow. halliwell. 50% similar → siserara, siserary

blow hard and loudly 50% similar → chuff, huff

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

deliver a quick blow to 50% similar → punch