IPA: /ʌnˈskruːpjʊləsli/
KK: /ʌnˈskrupjələsli/
In a way that shows no moral principles or concern for what is right or wrong.
He acted unscrupulously to gain an advantage over his competitors.
Unscrupulously → It is formed from "un-" (meaning not) and "scrupulus" (from Latin, meaning a small stone or a moral doubt). The word describes acting without moral hesitation or integrity, hence, not being scrupulous.
Think of someone who is 'not' ('un-') feeling any 'moral doubt' ('scrupulus') — that's why unscrupulously means acting without any moral concerns.