What does the cryptic crossword clue "Dinner hour used to be frantic for those needing it most (14)" mean?

The wordplay uses an anagram. anagram of DINNER + HOUR + USED = UNDERNOURISHED The answer is UNDERNOURISHED.

Dinner hour used to be frantic for those needing it most (14)

Daily Mail Cryptic #16448 | 8 Down | 2020-11-17 flower