23) 欠

qian

yawn

a person opening his mouth wide to yawn

23ax)  口

kou

23a) 吹

chui

blow

mouth (kou) + yawn (qian)

to breathe in as if yawning, then exhaling through the mouth to blow on an instrument

23bx) 二

er

23b) 次

ci

next; secondary

two (er) + yawn (qian)

after one person yawns the next one also yawns

this character is also used to count numbers of actions

23dx) 哥

ge

23dx-17b*) 歌

ge 

song

brother (ge) + yawn (qian)

23cx) 又

you

again

hand

23c) 欢

huan

joyful; joyous

hand/again (you) + yawn (qian)

to welcome someone joyfully with mouth open as yawning and hands open wide