type of strong, twilled fabric used for coats, etc., late 14c., from Old French serge (12c.), from Vulgar Latin *sarica, in Medieval Latin "cloth of wool mixed with silk or linen," from Latin serica (vestis) "silken (garment)," from serica, from Greek serike, fem. of serikos "silken" (see silk). The French word is the source of German sarsche, Danish sarge, etc. Also as a verb. Related: Serger.
word-forming element in chemistry, often interchangeable with -in (2), though modern use distinguishes them; early 19c., from French -ine, the suffix commonly used to form words for derived substances, hence its extended use in chemistry. It was applied unsystematically at first (as in aniline), but now has more restricted use.
The French suffix is from Latin -ina, fem. form of -inus, suffix used to form adjectives from nouns, and thus is identical with -ine (1).
Others are reading
<a href="https://www.etymonline.com/word/serine">Etymology of serine by etymonline</a>
Harper, D. (n.d.). Etymology of serine. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/serine