Facepalm
Noun · Slang & Abbreviations
Definitions
A reaction of embarrassment, disbelief, or frustration at an obvious mistake or avoidable decision. In technical chat it often labels bugs that should have been caught immediately.
In plain English: A reaction meaning a mistake was painfully obvious or embarrassing.
Example: "The outage was a facepalm moment once we realized the feature flag name was misspelled."