IPA: /ˈfɛk.ləs.li/
KK: /ˈfɛk lɪs li/
In a way that shows a lack of responsibility or effectiveness; carelessly or ineffectively.
He fecklessly spent all his savings on unnecessary items.
Fecklessly → It is formed from "feckless" (from Scots "feckless", meaning ineffective or lacking in purpose) and the suffix "-ly" (meaning in a manner of). The word "fecklessly" means in a manner that is ineffective or lacking in purpose.
Think of someone acting in a way that is 'ineffective' or 'lacking purpose' — that's what 'fecklessly' means.