su·per·cool 
(s′pər-kl)
(s′pər-kl)v. su·per·cooled, su·per·cool·ing, su·per·cools
v.tr.
To cool (a substance) below a phase-transition temperature without the transition occurring; for example, to cool a gas below the boiling point without condensation or to cool a liquid below the freezing point without solidification.
v.intr.
To become supercooled.