How many letters does the top answer for “the act of conferring legality or sanction or formal warrant” have?

The most common answer is authorisation (13 letters).

Crossword clue: the act of conferring legality or sanction or formal warrant

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

authorisation 13 letters wn-def

the act of conferring legality or sanction or formal warrant

empowerment 11 letters wn-def

the act of conferring legality or sanction or formal warrant