u̇mˈsüf noun
( -s )
Etymology: Arabic umm ṣūf sudd, literally, mother (i.e., source) of wool, from ṣūf-al-baḥr, a maritime plant, literally, wool of the sea
: a wiry grass ( Vossia procera ) that is found in the Nile and often makes up a considerable part of the river's sudd