yawning

Concise Oxford English Dictionary © 2008 Oxford University Press:
yawn/jɔːn/

▶verb

• 1 involuntarily open one's mouth wide and inhale deeply due to tiredness or boredom.

• 2 (usu. as adj. yawning) be wide open: a yawning chasm.

▶noun

• 1 an act of yawning.

• 2 informal a boring or tedious thing or event.

– derivatives
yawningly adverb.

– origin OE geonian, of Gmc origin.