How many letters does the top answer for “related to anagrams or containing or making an anagram” have?

The most common answer is anagrammatic (12 letters).

Crossword clue: related to anagrams or containing or making an anagram

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

anagrammatic 12 letters wn-def

related to anagrams or containing or making an anagram

anagrammatical 14 letters wn-def

related to anagrams or containing or making an anagram