Lexical Definition

‎διετής‎ dietḗs (dee-et-ace') two years old ^G:A
from ‎δίς‎ and ‎ἔτος‎

two years old.

• of two years (in age)

Abbott-Smith

** διετής, -ές (< δίς, ἔτος), [in LXX: II Mac 10:3 * ;]
1. lasting two years.
2. two years old: ἀπὸ δ. (sc. παιδός, or neuter; cf. I Ch 27:23, ἀπὸ εἰκοσαετοῦς), Mt 2:16.†

Abbott-Smith References

Liddell-Scott-Jones

διετής-ετής, ές,

or διετήςέτης, ες, of or lasting two years, χρόνος [διετήςετοῦς [prev. author] “HA” 500a11 ">Refs 5th c.BC+]; ἐπὶ διετήςετὲς ἡβᾶν to be two years past puberty, [Refs 4th c.BC+]

__II two years old, [Refs 4th c.BC+]
__III = {διετήςετήσιος}, [Refs 5th c.AD+]