When someone goes to extreme measures to get someone they loves attention
Bryan - Hey did you hear about that nutter who climbed on my roof and tried to climb through my window just to see if i was awake?

Sam - Ahh that guy must have been totally in love with you to be Doing A Neil
by Recycled Plastic June 25, 2010
Slang term for taking a crap/poo.
Oh Shit! Im going to explode! I have to go to the bathroom and Do the Neil.

Hes been in the bathroom for a long time, I think hes Doing the Neil.
by Phillip J. Dougan October 17, 2006