IPA: /dɪsˈlɔɪəli/
KK: /dɪsˈlɔɪəli/
In a way that shows a lack of loyalty or faithfulness to someone or something.
He acted disloyally by betraying his friends.
Disloyally → It is formed from "dis-" (meaning apart or away) and "loyal" (from Old French *leial*, meaning faithful or true) and the suffix "-ly" (meaning in a manner of). The word "disloyally" means in a manner that is unfaithful or not true to a commitment.
Think of being 'apart' ('dis-') from being 'faithful' ('loyal') — that's why disloyally means acting in an unfaithful manner.