IPA: /ˈpɪt.fɔːl/
KK: /ˈpɪtˌfɔl/
A hidden danger or difficulty that is not easily noticed.
Be careful of the pitfalls when starting a new business.
Pitfall → The word is formed from "pit" (from Old English "pytt", meaning a hole or cavity) and "fall" (from Old English "feallan", meaning to fall). A pitfall refers to a hidden danger or difficulty that one might fall into, metaphorically speaking.
Imagine a hidden hole ('pit') that you might accidentally 'fall' into — that's what a pitfall represents.