plant growth hormone, 1934, from German (1931), from Greek auxein "to increase" (from PIE root *aug- (1) "to increase") + chemical suffix -in (2).
Entries linking to auxin
*aug- 1
Proto-Indo-European root meaning "to increase." It forms all or part of: auction; augment; augmentative; augur; August; august; Augustus; author; authoritarian; authorize; auxiliary; auxin; eke (v.); inaugurate; nickname; waist; wax (v.1) "grow bigger or greater."
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit ojas- "strength," vaksayati "cause to grow;" Lithuanian augu, augti "to grow," aukštas "high, of superior rank;" Greek auxo "increase," auxein "to increase;" Gothic aukan "to grow, increase;" Latin augmentum "an increase, growth," augere "to increase, make big, enlarge, enrich;" Old English eacien "to increase," German wachsen, Gothic wahsjan "to grow, increase."
-in 2
word-forming element in chemistry, usually indicating a neutral substance, antibiotic, vitamin, or hormone; a modification and specialized use of -ine (2).