yawnstipated 

Feeling the need to yawn, but being unable to.

I'm sleepy and I really feel like I need to yawn, but I can't. I'm yawnstipated.

yawnstipated by Arbour0713 September 3, 2014

Yawnstipating 

A portmanteau of yawn and constipating. It’s the act of feeling like you’re going to yawn from something but not quite there. Something that is borderline boring.

The Da Vinci Code is very yawnstipating.

Yawnstipating by Razzball December 9, 2008