How many letters does the top answer for “toward a full side” have?

The most common answer is broadside (9 letters).

Crossword clue: toward a full side

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

broadside 9 letters wn-def

an advertisement intended for wide distribution

by the side; sidewise; toward, or from, the side. 50% similar → laterally

the side toward the wind 50% similar → weatherboard

to, toward or at one side 50% similar → sidelong, sideways