Gelid is just another way to say “extremely cold” or “icy”, either literally or figuratively.
From Merriam-Webster:
"Gelid" first appeared in English late in the 16th century, coming to our language from Latin "gelidus," which ultimately derives from the noun "gelu," meaning "frost" or "cold." (Our noun "gelatin," which can refer to an edible jelly that undergoes a cooling process as part of its formation, comes from a related Latin word: "gelare," meaning "to freeze.")
Sounds like a good name for a brand of frozen drinks or ice cream. Actually, there’s already a PC cooling company called Gelid Solutions. They have good taste!