IPA: /ʌnˈtoʊnd/
KK: /ʌnˈtoʊnd/
Not having a firm or well-defined shape, often referring to muscles that are not developed or strengthened.
After a long winter, she felt untoned and decided to start exercising again.
Untoned → It is formed from "un-" (meaning not) and "toned" (from the root "tone" which comes from Latin "tonus", meaning sound or tone). The word "untoned" means not having a tone or lacking tone.
Think of 'not' ('un-') having a 'sound' or 'tone' — that's why untoned means lacking tone.