ψύχω
psýchō
psoo'-kho
a primary verb; 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).

KJV translates as: wax cold