§ Elements in Quenya and Sindarin Names The Silmarillion

sîr 'river', from root sir- 'flow', in Ossiriand (the first element is from the stem of the numeral 'seven', Quenya otso, Sindarin odo), Sirion; also in Sirannon (the 'Gate-stream' of Moria) and Sirith ('a flowing', as tirith 'watching' from tir), a river in Gondor. With change of s to h in the middle of words it is present in Minhiriath 'between the rivers', the region between the Brandywine and the Greyflood; in Nanduhirion 'vale of dim streams', the Dimrill Dale (see nan[d] and dú), and in Ethir Anduin, the outflow or delta of Anduin (from et-sir).