Lexical Definition

‎ψύχω‎ psýchō (psoo'-kho) to cool ^G:V
a primary verb

wax cold.

• to breathe (voluntarily but gently, thus differing on the one hand from ‎πνέω‎, which denotes properly a forcible respiration
• and on the other from the base of ‎ἀήρ‎, which refers properly to an inanimate breeze), i.e. (by implication, of reduction of temperature by evaporation) to chill (figuratively)

Abbott-Smith

ψύχω [in LXX for קוּר, שׁטח ;]
to breathe, blow; hence, to make cool. Pass., to grow cool: metaph., Mt 24:12.†

Abbott-Smith References

Liddell-Scott-Jones

ψύχω,

[Refs 5th c.BC+]: future ψύξω [Refs 4th c.BC+]: aorist ἔψυξα [Refs 8th c.BC+]perfect ἔψῡχα Ps.-[Refs 2nd c.AD+] H.:—passive, future ψυχθήσομαι [Refs 5th c.BC+]: future [NT+2nd c.AD+]: aorist ἐψύχθην [ψύχω: ">Refs 5th c.BC+]aorist 2 ἐψύχην [ῠ] [Refs 5th c.BC+] P.: perfect ἔψυγμαι [Refs 5th c.BC+]:—breathe, blow, Ἀθήνη.. ἦκα μάλα ψύξασα [Refs 8th c.BC+]

__II make cool or cold (not necessarily by blowing), ἀπιὼν ἐπὶ μᾶλλον ψύχει (i.e. ὁ ἥλιος) [Refs 5th c.BC+]; opposed to θερμαίνω, [Refs 5th c.BC+]:—passive, grow cool or cold, [Refs 5th c.BC+]; of fire, to be put out, [Refs 5th c.BC+]will grow cold, [NT]
__II.2 cool, refresh, θάλπουσα καὶ ψύχουσα, of a nurse tending a child, [Refs]: intransitive in active, seek the cool air, [LXX+2nd c.BC+]
__II.3 chill, torment, ἀμφάκει κέντρῳ ψύχειν ψυχὰν ἐμάν (Meineke conjecture ψήχειν) [Refs 4th c.BC+]; of death, ψύξει σε δαίμων τῷ πεπρωμένῳ χρόνῳ [Refs 2nd c.AD+]:—passive, ψύχετ᾽ ἀμηχανίῃ [Refs 3rd c.BC+]
__II.4 metaphorically in passive, to be frigid, [Refs 3rd c.AD+]
__III dry, make dry, δάκρυα δ᾽ οὐ ψύχει γενέτης ἐμός [LXX]: air, ἱμάτια [Refs 2nd c.AD+]:—passive, [Refs 5th c.BC+]; οὗ τὰ σῦκα ψύχεται, gloss on{τρασιά}, [Refs 8th c.BC+] generally of drying in the wind, opposed to τερσήμεναι of drying in the sun, [Refs 8th c.BC+] [ῡ always, except in aorist 2 passive, see [Refs 5th c.BC+]

_{LSJ Scripture Refs: Matt.24.12 ☩ LXX.2Kgs.19.24 ☩ LXX.Jer.8.2}