Conniver \Con*niv"er\, n.
   One who connives.

Although the origin of the word conniver is from the Latin (connivere, meaning to blink or shut the eyes), the current usage appears to come from the Emerald Isle.  It was one of my wee Irish grandmother's favorite words.

To my Gram a conniver was a benign individual who would conveniently forget that they had done something improper, such as skipping Mass, or drinking milk directly from the bottle. 

Perhaps you can think of other applications of this word.

Janice