IPA: /ˈflæk.sɪd.li/
KK: /ˈflæk.sɪd.li/
In a way that is soft, weak, or lacking firmness.
The plant's leaves hung flaccidly after several days without water.
Flaccidly → It is formed from "flaccidus" (from Latin, meaning weak or limp) and the adverbial suffix "-ly" (meaning in a manner of). The word "flaccidly" means in a weak or limp manner.
Think of something that is 'weak' or 'limp' ('flaccidus') to remember that 'flaccidly' describes doing something in a weak manner.