IPA: /ʌnˈskɪl.fəli/
KK: /ʌnˈskɪl.fəl.i/
In a way that shows a lack of skill or ability.
He unskillfully tried to fix the broken machine, making it worse instead.
Unskillfully → It is formed from "un-" (meaning not) and "skill" (from Old Norse *skil*, meaning to discern or know) and "-fully" (meaning in a manner full of). The word "unskillfully" means in a manner that is not full of skill or lacking in skill.
Think of 'not' ('un-') being combined with 'skill' — this helps you remember that 'unskillfully' means doing something without skill.