yawn (v.) Look up yawn at Dictionary.com
c.1300, yenen, yonen, from Old English ginian, gionian "open the mouth wide, yawn, gape," from Proto-Germanic *gin- (cognates: Old Norse gina "to yawn," Dutch geeuwen, Old High German ginen, German gähnen "to yawn"), from PIE *ghai- "to yawn, gape" (cognates: Old Church Slavonic zijajo "to gape," Lithuanian žioju, Czech zivati "to yawn," Greek khainein, Latin hiare "to yawn, gape," Sanskrit vijihite "to gape, be ajar"). Modern spelling is from 16c. Related: Yawned; yawning.
yawn (n.) Look up yawn at Dictionary.com
"act of yawning," 1690s, from yawn (v.). Meaning "boring thing" is attested from 1889.