Lexical Definition

‎σιγή‎ sigḗ (see-gay') silence ^G:N-F
apparently from (to hiss, i.e. hist or hush)

silence.

Abbott-Smith

** σιγή, -ῆς, ἡ [in LXX: Wi 18:14, III Mac 3:23 * ;]
silence: Ac 21:40, Re 8:1.†

Abbott-Smith References

Liddell-Scott-Jones

σιγή-ή,

Doric dialect σιγά, ἡ, silence, σ. ἔχειν keep silence, [Refs 5th c.BC+]; σ. ποιήσασθαι make silence, [Refs 5th c.BC+]; πολλῶν φάρμακον κακῶν σ. [Refs 5th c.BC+]; δυσμενὴς τῇ σ. [Refs 5th c.BC+]; ἡ ἄγαν σ. [Refs 5th c.BC+]

__b in a mystical or religious sense,[NT]
__II σιγῇ, as adverb, in silence, the only case used by [Refs 8th c.BC+]; also διὰ σιγῆς, μετὰ σ., [Refs 5th c.BC+]: like{σῖγα}, as an exclamation, σιγῇ νῦν be silent now! [Refs 8th c.BC+]
__II.2 in an undertone, in a whisper, secretly [Refs 5th c.BC+]; σιγῇ ἔχειν τι keep it secret, [Refs 5th c.BC+]; σιγᾷ καλύψαι, σιγῇ στέγειν, κεύθειν, [Refs 5th c.BC+]
__II.3 with genitive, σιγῇ τινος unknown to him, [Refs 5th c.BC+]

_{LSJ Scripture Refs: Rev.8.1}