What does the cryptic crossword clue "Grow weak, left out in pain (7)" mean?

The definition is "pain". The wordplay uses a deletion. ANGUISH (deletion) = ANGUISH; definition: "pain" The answer is ANGUISH.

Grow weak, left out in pain (7)

Guardian Cryptic #27200 | 15 Across | 2017-05-18 flower