What does the cryptic crossword clue "Hurting Dad almost completely (7)" mean?

The wordplay uses a charade (building blocks). PA (synonym="PA") + IN (synonym="IN") + FUL (synonym="FUL") = PAINFUL The answer is PAINFUL.

Hurting Dad almost completely (7)

Guardian Cryptic #29375 | 24 Across | 2024-05-06 flower