What does the cryptic crossword clue "On part of journey, superficially damage trunks, say (7)" mean?

The wordplay uses a hidden word. LEG (synonym="part of journey") + WEAR (synonym="erode, superficially damage") = LEGWEAR The answer is LEGWEAR.

On part of journey, superficially damage trunks, say (7)

Guardian Cryptic #29403 | 21 Across | 2024-06-07 flower