look up any word, like cleveland steamer:
 
1.
Someone who is so unbelievably stupid that they could not have been conceived by conventional means. Their parents went to the pet shop, bought a package of Instakid® and poured it into water and put it in the oven at 365. 3 days later they had their full grown, dumb ass kid. Similar to sea monkeys.
Person 1: Alex is always driving drunk, I don't know what's wrong with him

Person 2: Alex is an instakid man
by idddddddddk June 09, 2014
 
2.
The kid of the person you are dating that quickly becomes almost your own because you spend so much time with them outside of your dating relationship.
I am in beginning stages of dating a man with a child and I also have a child. When I go anywhere with my child it is "expected" that my instakid (the son or daughter of my boyfriend) will also join us.
by marshmallowobsessed March 26, 2013