How many letters does the top answer for “a message received and understood” have?

The most common answer is info (4 letters).

Crossword clue: a message received and understood

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

info 4 letters wn-def

a message received and understood

information 11 letters wn-def

a message received and understood

be received or understood 67% similar → resonate