1 [usually + adverb/preposition] if a car or bicycle coasts, it moves without any effort from you or any power from the engine
2 to not try very hard to do something well - used to show disapproval :
Janey's teacher says she's just coasting at school.
Janey's teacher says she's just coasting at school.3 to be successful at something without much effort :
They scored three goals in the first half and from then on United were coasting.
They scored three goals in the first half and from then on United were coasting.4TTW to sail along the coast while staying close to land

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