Why Is Mincha Called Mincha?

From Rav Hutner ztz"l:

And from my Rebbi and a talmid of Rav Hutner - Rav Homnick Shlita:

See also Ramban [Shmos 12/6] the Tzlach and the sefer Avoda Brura Brachos 502-503 who collected a lot of explanations.