mid-15c., "handle clumsily," possibly from Old Norse falma "to fumble, grope." Similar words in Scandinavian and North Sea Germanic (Swedish fumla; Dutch fommelen) suggest onomatopoeia from a sound felt to indicate clumsiness (compare bumble, stumble, and obsolete English famble, fimble of roughly the same meaning). Intransitive sense "do or seek awkwardly" is from 1530s. Sense in football is from 1889. Related: Fumbled; fumbling.
<a href="https://www.etymonline.com/word/fumbling">Etymology of fumbling by etymonline</a>
Harper, D. (n.d.). Etymology of fumbling. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/fumbling