Synchronized rimming 

The act of licking each other's assholes simultaneously. It is believed to be one the original Olympic sports.

Synchronized rimming is the only sport my gf and I genuinely enjoy together.

Synchronized rimming by ElAteo June 10, 2015

synchronous unequivocal postulate

A scientific formula designed to bring clarity to radio frequencies (per the radio frequency spectrum) by determining calculated degrees of readjustments, troubleshooting networks by ensuring the desired stations (hopset IDs) are in synch, and filtering out all discrepancies by reinforcing equilibrium to the respective signals between radio units.

LCpl Joe: "Hey I tried getting a radio check with you, but I hear static and the radio reads 'check synch input.' What's up with that?"
LCpl Dirt: "Well that's exactly it! Use the SUP method."
LCpl Joe: The what?
LCpl Dirt: "You know. SUP. Synchronous Unequivocal Postulate. It's another way to troubleshoot and establish your signal."
LCpl Joe: "Very well. Thanks man. I didn't learn that in comm school."

synchronous unequivocal postulate by jotahu May 24, 2016

Synchronisitis 

When you randomly check the time and the minutes are almost always the same.

"... Did you ever notice that about eleven? Every time you look at your clock it's something eleven?"-Roseanne Barr Synchronisitis

Synchronisitis by Jch1985 October 4, 2019

synchronization

The activity of two or more things happening at the same rate.

"Seventeen are always in synchronization"

"Seventeen are deserving of best male dance performance because of their crazy synchronization"

synchronization by wzsnippiercing February 1, 2020

Synchronized Wiping 

Making sure your windshield wipers are in synch with those of the other drivers moving towards your vehicle, as not to look like a bitch.

I don't want to be the only one on the road with my wipers going extra fast so I will practice Synchronized Wiping

I can hardly see out my windshield, but at least I'm not a pussy!

I am asserting my manliness by turning my wipers on, extra slow, during the torrential downpour

Synchronized Wiping by WAFTW September 5, 2010

spontaneous synchronized dance 

An unplanned but obviously pre-choreographed outburst of dancing within a normal, non-party setting by a group of three or more people, usually including singing, as in most films classified as "musicals." Often abbreviated as SSD.

"In an attempt to avoid a fight which they knew they couldn't win, the smaller of the two gangs immediately broke into spontaneous synchronized dance, hoping the movements of their bodies and voices united in song would make the larger gang reconsider their course of action."

spontaneous synchronized dance by Tom M. October 16, 2007

Synchronized 

GFriend (like seriously look at their dance videos so sync)

GFriend is synchronized af. (ik it's dumb but bear with me here)

Stan GFriend.

Synchronized by KPOP not Gaypop January 22, 2019