How many letters does the top answer for “in a direction opposite to the direction in which the hands of a clock move” have?

The most common answer is anticlockwise (13 letters).

Crossword clue: in a direction opposite to the direction in which the hands of a clock move

anticlockwise, counterclockwise.

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

anticlockwise 13 letters wn-def

in the direction opposite to the rotation of the hands of a clock

counterclockwise 16 letters wn-def

in the direction opposite to the rotation of the hands of a clock

in the direction that the hands of a clock move 80% similar → clockwise

in the direction opposite to the rotation of the hands of a clock 67% similar → anticlockwise, counterclockwise