IPA: /ˈstʌmblər/
KK: /ˈstʌmblər/
A person who trips or falls while walking or moving, often in a clumsy manner.
The stumbler fell over a rock while hiking on the trail.
Stumbler → The word is formed from "stumble" (from Old English *stumblian*, meaning to trip or fall) and the suffix "-er" (meaning a person who). A stumbler is a person who trips or falls while walking.
Think of someone who 'trips' ('stumble') while walking — the '-er' indicates that this person is doing the action, making them a stumbler.