full-grown

From Middle English *fulgrowen, fulgrowe, ful growe, equivalent to full +‎ grown. Compare Middle English fulwaxen, fullwaxen (“full-grown”), from Old English fullweaxen (“full-grown”).

full-grown (not comparable)

1. (of living things, especially animals) Fully developed; adult.
2. Fully developed in a broader sense; complete, at one’s height.
   • 1850, [Alfred, Lord Tennyson], In Memoriam, London: Edward Moxon, […], →OCLC, Canto XXXIX, page 61:

     […] And, doubtless, unto thee is given
     ⁠A life that bears immortal fruit
     ⁠In such great offices as suit
     The full-grown energies of heaven.

• big, developed, grown up; see also Thesaurus:full-grown

• full-grownness