How many letters does the top answer for “of or relating to thailand” have?

The most common answer is siamese (7 letters).

Crossword clue: of or relating to thailand

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

siamese 7 letters wn-def

a branch of the Tai languages

thai 4 letters wn-def

a branch of the Tai languages

of or relating to words 50% similar → lexical