Definition

A casual greeting asking "What's up?" or "How are you?" Often used in laid-back conversation to check in with someone without expecting a detailed response.

Example Usage

I ran into my buddy at the store and was like, 'Sizup?' He said 'Not much, just grabbing groceries.'

Source: Urban Dictionary (https://www.urbandictionary.com/define.php?term=sizup&defid=6860)