A vlei () is a shallow minor lake, mostly of a seasonal or intermittent nature. It even might refer to seasonal ponds or marshy patches where frogs and similar marsh dwellers breed. Commonly, vleis vary in their extent, or even in the presence or absence of water, according to the fall of rain or dryness of the season. In terms of water salinity, vleis may be freshwater, saltwater, or brackish. * vlei frog.
== Etymology == The word ' is used predominantly in South Africa. It is an Afrikaans word derived from the Middle Dutch word for "valley" ('). In Afrikaans, however, its meaning changed into that of the shallow lake. The Afrikaans and modern Dutch word for "valley" is ''''.
The North American placename vlaie is cognate with '''', having the same Middle Dutch derivation.