How many letters does the top answer for “derived from experiment and observation rather than theory” have?

The most common answer is empiric (7 letters).

Crossword clue: derived from experiment and observation rather than theory

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

empiric 7 letters wn-def

derived from experiment and observation rather than theory

empirical 9 letters wn-def

derived from experiment and observation rather than theory