Sinimäe (Sinimägi)

Blue mountain. See Vana-Mustamäe. The etymology of sinine (blue) is elusive to say the least... EES gives the rather dismissive ‘?’ symbol next to a possible algindoiraani, or early Indo-Iranian, with possible great-aunts as the Pashto or Afghani šīn, meaning blue or green, and ignores the blatantly obvious Russian next door of си́ний (siniy). So perhaps it’s not that blatant after all. Cognates exist in various Slavic languages as far back as Proto-Slavic sivъ (siv) (5^th to 9^th C) and a loan does seem likely, although not necessarily from Russian. Given the complex crush of candidate origins and cognates ranging from Sanskrit śyāma, श्याम (dark colors), Lithuanian šývas (greyish white), Latin cĭnis (ash), Greek κυανός (cyan, ‘blue substance’, but also used to describe Hector’s hair), PIE *k̂eu- (to shine, or bright) and Hittite kuwanna (copper blue), along with German schön (beautiful) and English ‘sheen’, I shall step quietly over this one and maybe, one day, look at it in my language blog (see frogologue.com or frogologoblog), but don’t count on it.