Lexical Definition

‎ἄδηλος‎ ádēlos (ad'-ay-los) unclear ^G:A
from ‎Α‎ (as a negative particle) and ‎δῆλος‎

appear not, uncertain.

• hidden, figuratively, indistinct

Abbott-Smith

ἄ-δηλος, -ον (< δῆλος), [in LXX: Ps 50 (51):6 (בַּטֻּחוֹת);]

1. unseen, unobserved, not manifest (Ps 50 (51):6): Lk 11:44.
2. uncertain, indistinct: I Co 14:8.†

Abbott-Smith References

Liddell-Scott-Jones

ἄδηλος-ος, ον,

unseen, invisible, of a fish, ποιεῖν ἑαυτὸν ἄ.[Refs 4th c.BC+]; ἄ. χιτών, of the hyaloid membrane of the eye, [[Refs 2nd c.AD+]; unknown, obscure, [Refs 8th c.BC+]; ἐὰν δὲ.. ἄ. ὁ κτείνας ᾖ [Refs]; of troops, ἄ. τοῖς πολεμίοις[Refs 5th c.BC+]

__II mostly of things, ἄ. θάνατοι death by an unknown hand, [Refs 5th c.BC+]; ἄ. ἔχθρα secret enmity, [Refs 5th c.BC+]; ῥεῖ πᾶν ἄδηλοςον melts all to nothing, [Refs 5th c.BC+]; inscrutable, [Refs 5th c.BC+]
__II.b neuter, ἄδηλοςόν [ἐστι] εἰ.. it is uncertain whether.., [Refs 5th c.BC+]; ἄ. μή.. [Refs 5th c.BC+]; also ἄ. agreeing with the subject (like δίκαιός εἰμι), παῖδες ἄ. ὁποτέρων, ={ἄδηλοςον ὁποτέρων παῖδές εἰσιν}, [Refs 5th c.BC+]; ἀδήλοις.. πῶς ἀποβήσεται, ={ἃ ἄ. ἐστι πῶς ἀ}., [Refs 5th c.BC+]
__II.2 not evident to sense, ὄψις τῶν ἀ. τὰ φαινόμενα[Refs 5th c.BC+]; opposed to φανερόν, [Refs 1st c.BC+]; opposed to ἐναργές,[Refs 2nd c.AD+]
__II.3 unintelligible, φωνή[NT]
__II.4 unproved, [Refs]
__III adverb -λως secretly, [Refs 5th c.BC+]: superlative -ότατα[Refs]

_{LSJ Scripture Refs: 1Cor.14.8}