How many letters does the top answer for “involving or operating in several nations or nationalities” have?

The most common answer is multinational (13 letters).

Crossword clue: involving or operating in several nations or nationalities

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

multinational 13 letters wn-def

involving or operating in several nations or nationalities

transnational 13 letters wn-def

involving or operating in several nations or nationalities