What does the cryptic crossword clue "Trench dug, yah boo sucks! (2-2)" mean?

The definition is "Trench dug, yah boo sucks!". The wordplay uses a double definition. Double definition The answer is HAHA.

Trench dug, yah boo sucks! (2-2)

Guardian Cryptic #29426 | 22 Across | 2024-07-04 flower