Instaflex 

When people post photos on Instagram trying to stunt

These ho's fillin' up my instaflex thinking they special.

Instaflex by Mayoyo January 1, 2013

instasex 

Verb - when two people continue to like each other's photos without any other contact. You both know what you're thinking

She likes all of his photos and he likes hers back. They both think the other are cute and secretly just want to have intercourse but instead they'll have instasex

instasex by Yomomma669 October 3, 2013

instaflush

A tecnhique of instant, pre-wipe toilet flushing, used when a particuarly bad smell is anticipated, often in a guest's house.

I was at my bird's house last night and had to instaflush. Just couldn't risk it in the downstairs toilet

instaflush by Asthmatic Mule December 26, 2014

Instaflirting

When two people go back and forth liking one another's photos flirtaciously eventually causing one to DM the other

Who is the @*******

I don't know why?
Because every time I like one of her photos, she likes one of mine.
She is instaflirting with you, you should message her

Instaflirting by Hink68PMMF September 9, 2016

Instaflaccid 

An event causing an erection to become flaccid almost instantly.

That cottage cheese face was an instaflaccid.

Instaflaccid by PeteZar33 January 17, 2009

instalegacy 

Code created that becomes legacy code the moment it is written. Typically written by someone who has been allowed to code when they clearly shouldn't have been.

Woah! This new mobile-app code is instalegacy. Is that a GOTO?

instalegacy by meadsteve March 2, 2014

Instaleg syndrome 

A neurological syndrome characterized by unilateral or bilateral numbness of lower extremities while sitting on the toilet for long period of time reviewing social media. This may in some cases extend up to and including your buttocks and perineum.

Hey dude, get off the shitter or your gonna get Instaleg syndrome!

Instaleg syndrome by Dr Gasman May 13, 2016