Two expressions meaning water are megha-prasara and megha-prasava. As
you can readily appreciate by just looking at these expressions, they
are not single words!! They are either phrases or compound words and
they describe one of the sources of water, that is, the clouds. They
may be translated as cloud – given and cloud –born. Even in the
English, any one should be able to form compounds or expressions such
as the above, to mean water. Such expressions should not be reckoned as
words for water.
megha-prasava : megha is a Dravidian term,
coming from the root “me” which means above or high above. Ku + am are
suffixes. Pra-sava, is Tamil too, pra being derived from puRa, means
outside. Sara is actually from chaaRu, essence.
Hence the whole expressions means “coming from the (outside of ) the clouds.
SIVAMAALA LITERARY 