IPA: /ʌnˈʧɪvəlrəsli/
KK: /ʌnˈʧɪvəlrəsli/
In a way that is not honorable or courteous, especially in behavior towards others.
He acted unchivalrously by not helping her when she needed it.
Unchivalrously → It is formed from "un-" (meaning not), "chivalrous" (from Old French *chevaleresque*, meaning knightly or gallant), and "-ly" (meaning in a manner of). The word describes behaving in a manner that is not knightly or gallant.
Think of 'not' ('un-') behaving in a 'knightly' way ('chivalrous') — that's why unchivalrously means acting without gallantry.