IMpounce 

When someone jumps on you immediately when you sign in to messenger or another instant messaging application.

I *just* wanted to check my emails and go to bed when Steve IMpounced me and I had to chat for another half hour!

IMpounce by jbng October 23, 2007

Dog Impounder

entering into a dead-end relationship with a cheating/unfaithful guy; treat him like a pet until he becomes too emotionally attached; allowing him to stray as he pleases, knowing he will find his way right back to you...

A girl who deals with an unfaithful/cheating guy who has made it clear that he's not leaving his wife/main girl; but you take him in, giving him special treatment like a pet, causing him to become emotionally attached (Dog Impounder). If he strays away, you know he is too caught up to leave & will always keep coming back...

Dog Impounder by BrownSugar0929 March 15, 2014

IM-pounce 

To initiate conversation, the second a person logs into their IM.

X)waiting for sign in
Y)signs in
X)IM-POUNCE

IM-pounce by Silent0809 February 19, 2009