Lexical Definition

‎γαλήνη‎ galḗnē (gal-ay'-nay) calm ^G:N-F
of uncertain derivation

calm.

• tranquillity

Abbott-Smith

* γαλήνη, -ης, ἡ,
a calm: Mt 8:26, Mk 4:39, Lk 8:24.†

Abbott-Smith References

Liddell-Scott-Jones

γαλήνη-η, ἡ,

stillness of the sea, calm (γ. μὲν ἐν θαλάσσῃ νηνεμία δ᾽ ἐν ἀέρι [Refs 8th c.BC+]; οἱ δ᾽ ἐλόωσι γαλήνην will sail the calm sea, [Refs]; stillness of deep waters, [Refs 5th c.BC+]: metaphorically of the mind, calmness, serenity, φρόνημα νηνέμου γαλάνας [Refs 4th c.BC+]; ἐν γαλήνῃ in calm, quiet, [Refs 5th c.BC+]

__II lead sulphide, galena, [Refs 1st c.AD+]
__III name of an antidote, [Refs 1st c.AD+] accusative to [Refs 6th c.AD+]; perhaps akin to γελάω.)