adj. Producing cold.

Data for determining the frigorific effect of the ice on the temperature of the Pole.
An account of the artic regions, William Scoresby (1820)

It’s summer right now but when winter comes again it’ll be friggin’ frigorific! “Frig” as in “frigid” means, of course, cold. Β And “-rific” is uninterestingly enough a respelling of the French word “frigorifique.”

For the purpose of my own satisfaction let’s say that it’s from “terrific,” so that Frigorific now means “terrifically cold.” People make up words all the time, who says I can’t change definitions or etymologies?

The original meaning was used in science but, as always, figurative use is much more fun.

A frigorific torpidity of despair chilled every sense.
Zastrozzi, Percy Bysshe Shelley (1810)

He sure had a way with words! And now you can too.

“Mom! This meatloaf is frigorific!” … “Silence, you old frigorific hag!” … “The frigorific weather and bigger rigor made him wiggle and wriggle like Tigger and he lost his vigor.” Say that one five times fast.