IPA: /kænˈtæŋkərəsli/
KK: /kæn'tæŋkərəsli/
In a way that is difficult to deal with or irritable, often showing a bad temper.
He cantankerously refused to cooperate with the team.
Cantankerously → It is formed from "cantankerous" (originating from a dialectal variant of the word, possibly from the Middle English *cantankere*, meaning ill-tempered or quarrelsome) and the suffix "-ly" (meaning in a manner of). The word "cantankerously" means in a manner that is ill-tempered or quarrelsome.
Think of someone behaving in an ill-tempered way — that's what 'cantankerously' means, describing actions done in a quarrelsome manner.