C16: perhaps related to quake; compare Middle Low German quabbe
quag in American English
(kwæg; kwɑg)
noun
Rare
a bog or marsh
quag in American English
(kwæɡ, kwɑɡ)
noun
a quagmire
Word origin
[1580–90; expressive word, obscurely akin to quake]This word is first recorded in the period 1580–90. Other words that entered Englishat around the same time include: classical, cockpit, critical, scramble, stigma