What does the cryptic crossword clue "A muted inventor's represented as lacking expression (15)" mean?

The wordplay uses an anagram. anagram of A + MUTED + INVENTOR'S = UNDEMONSTRATIVE The answer is UNDEMONSTRATIVE.

A muted inventor's represented as lacking expression (15)

Daily Mail Cryptic #17071 | 7 Down | 2023-04-07 flower