Definitions by Spare101

spareface 

interj.

Used to express apathy or indicate a lack of interest or concern, also careface.

Literally a face that is 'spare', an evolution of talk to the hand (because the face isn't listening).

Susan: Hey my phone's so much cooler than yours it can even talk to itself!
Clint: Spareface!

spareface by Spare101 June 6, 2013