grainyoudaoicibaDictYouDict[grain 词源字典]
grain: [13] Grain comes via Old French from Latin grānum ‘seed’. Its prehistoric Indo- European ancestor was *grnóm, literally ‘worndown particle’, which also produced English corn, and it has given English a remarkably wide range of related forms: not just obvious derivatives like granary [16], granule [17], and ingrained [16], but also garner [12] (originally a noun derived from Latin grānārium ‘granary’), gram ‘chick-pea’ [18] (from the Portuguese descendant of grānum, now mainly encountered in ‘gram flour’), grange, granite, gravy, grenade, and the second halves of filigree and pomegranate.
=> filigree, garner, granary, granite, gravy, grenade, ingrained, pomegranate[grain etymology, grain origin, 英语词源]
ingrainyoudaoicibaDictYouDict
ingrain: [17] Ingrain means literally ‘work into the grain’ (of fabric, originally) – whence the main metaphorical sense of ingrained, ‘deepseated’. But there is much more to the story of ingrain than that. Its ultimate source was engrainer ‘dye’, an Old French verb based on graine ‘cochineal dye’. English borrowed this in the 14th century as engrain ‘dye crimson with cochineal’, which remained a live sense of the word into the 17th century.

Gradually awareness of the word’s original specific connections with the colour crimson died out, and the verb was virtually formed anew in the mid 17th century using the concept of the grain or ‘texture’ of cloth, but the spelling engrain remained, and remains as a secondary variant to this day, to remind us of the word’s origins.

=> grain
epeiric (adj.)youdaoicibaDictYouDict
in reference to seas covering continental shelves, 1915, from Greek epeiros "mainland, land, continent," from PIE root *apero- "shore" (cognates: Old English ofer "bank, rim, shore," Old Frisian over "bank") + -ic.
As the term "continental deposits" in this sense is now ingrained in Geology, we can no longer use Dana's "continental seas" without raising a question in the mind as to what is meant when their deposits are considered. For this reason we propose here to use epeiric seas (meaning seas that lie upon the continents) for the bodies of water that lie within the continents in the downwarps of the continental masses. [Louis V. Pirsson, "A Text-Book of Geology," 1915]
ingrain (v.)youdaoicibaDictYouDict
1766, see engrain. Figurative use, of qualities, habits, etc., attested from 1851 (in ingrained). Of dyed carpets, etc., 1766, from in grain.