What does the cryptic crossword clue "Annoyance over time in transportation of oil? (6)" mean?

The wordplay uses a charade (building blocks). PIP (synonym="annoyance, as in “get the pip”") + AGE (synonym="time") = PIPAGE The answer is PIPAGE.

Annoyance over time in transportation of oil? (6)

Guardian Cryptic #29546 | 16 Down | 2024-11-21 flower