Instastalker 

A person who likes, comments or follows a user of social media without having any real life connection to them or who you may actually dislike in the real world.

Chad to friend - "hey, I just liked John's photo on Instagram and we haven't spoken in months!"

Friend to Chad - "Damn, Chad, you're such an INSTASTALKER!!!"

Instastalker by Uniquethinker87 November 5, 2014

instastalker 

A friend who follows all of your friends, even if they don't know the person

That girl is an instastalker!

instastalker by definethis1 June 9, 2014

Instastalking

When you browse through someone's Instagram page for a period of time without liking or commenting on any of their photos or videos

Person A: Dude, have you seen Person C?! She is so hot!

Person B: Yeah, I know right, I spent like all of last night instastalking her.

Instastalking by DoubleM_2000 June 9, 2014

Instastalk 

verb:
To stalk someone on Instagram.

This is a development from the traditional Facebook stalk, as there are many more users that will allow their Instagram account to be public, and therefore open to Instastalkers (noun).

I know she goes to the gym, because I instastalked her.

I've made my Instagram account public, so everyone can instastalk me.

Instastalk by Buggiful January 30, 2014

Instastalking

The act of looking through someone's Instagram without liking photos and videos. This can also be done by looking at photos the user was tagged or by clicking on people who were tagged in the user's photos.

james has been Instastalking Aly and he is currently 106 weeks into her Instagram.

Instastalking by workoutsbymanny June 12, 2015

Instastalk 

When someone you have just met friends or messages you on facebook via smartphone during the time it took you to leave the bar and get home.

"Holy sh*t, she instastalked me. I can't decide if that's cool or not."

Or

"Don't friend her yet, your too close to instastalk territory."

Instastalk by Drewsmits February 9, 2010

Insta Stalker 

When someone views your instagram profile and watches your stories without following you.

John is an Insta stalker he watches my stories without following me.

Insta Stalker by OnTop January 21, 2020