Lexical Definition

‎μονογενής‎ monogenḗs (mon-og-en-ace') unique G:A
from ‎μόνος‎ and ‎γίνομαι‎

only (begotten, child).

Usage: 5 forms in 13 verses
Form Translated As     In Verse(s)
μονογενῆ one and only 1John.4.9
only begotten John.3.16 • Heb.11.17
μονογενὴσ an only Luke.8.42
only begotten Luke.7.12 • John.1.18
μονογενοῦσ of an only begotten John.1.14
only begotten John.3.18
μονογενήσ an only child LXX.Judg.11.34 • LXX.Ps.25.16 • Luke.9.38
μονογενή my only child LXX.Ps.22.20 • LXX.Ps.35.17

Abbott-Smith

μονογενής, -ές (< μόνος, γένος), [in LXX: Jg 11:34, Ps 21 (22):20 24 (25):16 34 (35):17 (יָחִיד), To 3:15 6:10, 14 8:17, Wi 7:22, Ba 4:16*;]
only, only begotten (DCG, ii, 281), of sons and daughters: Lk 7:12 8:42 9:38, He 11:17; of Christ, Jo 3:16, 18, I Jo 4:9; μ. παρὰ πατρός, Jo 1:14; μ. θεός, Jo 1:18.†

Abbott-Smith References

Book Refs
Judges 11:34
Psalms 22:20 · 25:16 · 35:17
Luke 7:12 · 8:42 · 9:38
John 1:14 · 1:18 · 3:16 · 3:18
Hebrews 11:17
1 John 4:9

Liddell-Scott-Jones

μονογενής-γενής, ές,

Epic dialect and Ionic dialect μουνο-, (γένος) the only member of a kin or kind: hence, generally, only, single, παῖς [NT+8th c.BC+]; of Hecate, [Refs 8th c.BC+]

__2 unique, of τὸ ὄν, [Refs 5th c.BC+]
__3 μ. αἷμα one and the same blood, uncertain reading in [Refs 5th c.BC+]
__4 Grammars, having one form for all genders, [Refs 2nd c.AD+]
__5 name of the foot ¯ ¯ ¯ ?\~X, [Refs 7th c.AD+]
__II adverb -νῶς, φέρεται μ. ἐν ἑνὶ τόπῳ grows only in one place, [Refs]
__II.2 in a unique manner, [Refs 6th c.AD+]

LSJ Scripture Refs: John.1.14