indigoyoudaoicibaDictYouDict
indigo: [16] Etymologically indigo, a blue dye, is the ‘Indian dye’ – so named because supplies of it were obtained from India. The term is an ancient one. It originated in Greek indikón, literally the ‘Indian substance’, a derivative of the adjective Indikós ‘Indian’, and passed via Latin indicum and Spanish indico into English as indico.

This was replaced in the 17th century by the Portuguese form indigo, and it was Portuguese influence, stemming from their commercial activities in India, that really established the term among the European languages (hitherto the commoner term for the dye had been anil, a word of Sanskrit origins). (The name India, incidentally, to which indigo is related, comes ultimately from Old Persian hiñd’u, which originally meant ‘river’, was subsequently applied specifically to the river Indus, and finally became the name for the country through which the Indus flowed.)
=> india
stem (v.1)youdaoicibaDictYouDict
"to hold back," early 14c., from a Scandinavian source, such as Old Norse stemma "to stop, dam up; be stopped, abate," from Proto-Germanic *stamjan (cognates: Swedish stämma, Old Saxon stemmian, Middle Dutch stemon, German stemmen "stop, resist, oppose"), from PIE root *stem- "to strike against something" (cognates: Lithuanian stumiu "thrust, push"). Not connected to stem (n.). Related: Stemmed; stemming. Phrase to stem the tide is literally "to hold back the tide," but often is confused with stem (v.2) "make headway against."

Verbal phrase stems from (1932, American English), perhaps is from stem (v.) in the sense "to rise, mount up, have origin in" (1570s), or is influenced by or translates German stammen aus, probably from a figurative sense represented by English stem (n.) in the sense of "stock of a family, line of descent" (c. 1540; cognates: family tree, and German stammvater "tribal ancestor," literally "stem-father").
stem (v.2)youdaoicibaDictYouDict
"make headway by sailing, head in a certain course," late 14c., literally "to push the stem through," from stem (n.) in the "ship post" sense (here the post at the prow of the ship). Related: Stemmed; stemming.