IPA: /ʌnˈwɛl/
KK: /ʌnˈwɛl/
Feeling sick or not healthy; having a condition that makes you feel bad.
She stayed home from work because she was feeling unwell.
Unwell → It is formed from "un-" (meaning not) and "well" (from Old English "wel", meaning in good health or satisfactory). The word "unwell" means not in good health or feeling ill.
Think of 'not' ('un-') being added to 'well', which means healthy. This helps you remember that 'unwell' means not feeling healthy.