How many letters does the top answer for “of or relating to a person who is subordinate to another” have?

The most common answer is adjunct (7 letters).

Crossword clue: of or relating to a person who is subordinate to another

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

adjunct 7 letters wn-def

something added to another thing but not an essential part of it

assistant 9 letters wn-def

a person who contributes to the fulfillment of a need or furtherance of an effort or purpose

another word for subordinate 50% similar → underling