/sooh'peuhr koohl"/ , v.t.
1. to cool (a liquid) below its freezing point without producing solidification or crystallization; undercool.
v.i.
2. to become supercooled.
adj.
3. very cool in temperature, esp. of the maximum coolness possible: used as a setting on air conditioners.
4. Slang. very cool; very sophisticated, up-to-date, unemotional, etc.
[ 1905-10; SUPER- + COOL ]