checkman 

A loser in an IRC chan who is always fapping to the pictures posted.

see that kid fapping to my bank? he's such a checkman

checkman by Angel2_Mage November 7, 2010

Checkmate 

What you say when you bring in an argument so powerful that your debate opponent is unable to respond to it.

Bananas prove god exists. CHECKMATE atheists.

Checkmate by Friendless Fellow August 2, 2019

Blue Checkmark 

Someone on Twitter who thinks they are famous but in reality nobody has heard of (usually a B-list celebrity or a journalist who writes for a little-known leftist publication). The main factor which separates them from the verified accounts belonging to real celebrities is that the Blue Checkmarks lack the self-awareness to realize that nobody really cares about their opinions, yet they act as though they are God's gift to political discourse as they spout their self-righteous hot takes on Twitter.

Of course all of the Blue Checkmarks came out in droves to virtue signal about the latest election news.

Blue Checkmark by Russian Dumplings November 24, 2020

Ice skater checkmate

The Ice skater checkmate is a checkmate where the rook or the queen checkmates the king that is blocked by all three of his pawns after the king has castled.

OH MY GOD CHAT I DID THE "ICE SKATER CHECKMATE" BING BANG BOOM

Ice skater checkmate by LustBird May 26, 2020

Blue Checkmark 

a term describing someone who is verified on Twitter, giving them a blue checkmark, hence the name.
the term is a pejorative, predominantly used by right-wing people to describe left-wing journalists who tweet things that either are stupid or exactly what they expected from a person with the checkmark. usually both

the Blue Checkmarks are dishing out hot takes again

Blue Checkmark by gingerwithasoul_ July 4, 2018

what's up checkmark 

A reply made by youtube commenters when a verified youtuber leaves a comment on someone else's video

Youtuber: Great video, man!
Reply: what's up checkmark

what's up checkmark by Redthetroll May 16, 2021

Checkmarks 

People on Twitter with blue checkmarks next to their names, usually some journalist you've never heard of.

I couldn't believe how many checkmarks were in his comments freaking tf out lol

Checkmarks by searaft June 19, 2018