Keener is more benign than brown-noser, but Canadians will use it with a subtle hint of irony or sarcasm to indicate politely that the "keener' is indeed a brow

Keener is more benign than brown-noser, but Canadians will use it with a subtle hint of irony or sarcasm to indicate politely that the "keener' is indeed a brown-noser or amusing try hard.