1
chugged, chugging
no obj. emit a series of regular muffled explosive sounds, as of an engine running slowly（如引擎慢慢运转般）嘎嚓作响：he could hear the pipes chugging.
他能听见管子嘎嚓作响。
1.1
- no obj., with adverbial of direction(of a vehicle or boat) move slowly making such sounds（车, 船）嘎嚓嘎嚓缓慢行驶：
a cabin cruiser was chugging down the river.
游艇正沿河缓慢行驶。
- a muffled explosive sound or a series of such sounds嘎嚓声：
the chug of a motor boat.
摩托艇的嘎嚓声。
词源
mid 19th cent. (as a noun)： imitative.