Dafuq is a slang interjection used to react to something confusing, absurd, or nonsensical. It's a phonetic squish of 'what the fuck,' typically written all lowercase with no spaces or punctuation1. The term picked up steam online in the late 2000s through image macros and reaction posts, most famously the wide-eyed Snape shot from Harry Potter3.

Beyond the image macro, dafuq works as a text-based reply to anything strange, often dropped as a one-word question in comments when something defies explanation1. The spelling deliberately mimics slurred pronunciation of the original phrase, giving it a more conversational tone than the older abbreviation 'wtf'1.

Dafuq is typically dropped as a one-word reply or an opening word (as in 'Dafuq did I just watch?') in comments and texts when something looks strange or defies explanation1. In its image macro form, the word usually captions a wide-eyed startled reaction shot placed below a confusing image1.