D defs.my
Entry 1 sense Webster, 1913

auxin

· aux·in · IPA
01 n. a substance which, in small concentrations, promotes root formation, bud growth, or certain other processes such as fruit ripening or leaf …
  1. 1.
    a substance which, in small concentrations, promotes root formation, bud growth, or certain other processes such as fruit ripening or leaf drop in plants.