Lexical Definition

‎τεσσαρακονταετής‎ tessarakontaetḗs (tes-sar-ak-on-tah-et-ace') forty years ^G:A
from ‎τεσσαράκοντα‎ and ‎ἔτος‎

(+ full, of) forty years (old).

• of forty years of age

Abbott-Smith

** τεσσερακονταετής (T, -έτης; Rec. τεσσαρ-, v. supr.), -ές
of forty years, forty years old: Ac 7:23 13:18.†

Abbott-Smith References

Liddell-Scott-Jones

τεσσαρακονταετής-ετής, ές,

forty years old, [NT+8th c.BC+]:—Attic dialect feminine τεττᾰρᾰκοντᾰέτις, ιδος, [Refs 5th c.BC+]: masculine also τεσσᾰρᾰκοντούτης, [Refs 2nd c.AD+], (τεττ-) [Refs 2nd c.AD+]

_{LSJ Scripture Refs: Acts.7.23}