A quagmire refers to either an area of soggy ground or a situation full of problems that is difficult to get out of. Examples of the first definition include areas of bogs and swamps that people sink into and become stuck.
A common use of the second definitions occurs when political talks or military interventions become bogged down without an apparent resolution.
The first recorded use of the word "quagmire" dates to the late 16th century, where it combined the now obsolete "quag," which meant bog or marsh, with the word "mire," which also meant marsh. The first use of "quagmire" in reference to a difficult situation occurred in the late 18th century.