coolest
Least warm, figuratively
Coolest is the superlative of cool—the most fashionable, impressive, or admired among a group: She was the coolest kid in school.
It can describe temperature (the coolest day of summer) but more often carries the slang sense of ultimate approval or social cachet: That's the coolest thing I've ever seen.
Superlative of tranquil
- collectedCalm and self-possessed
- unflappableImpossible to disturb
- poisedCalm and controlled
- sereneUntroubled and composed
level-headed · unfazed · stoic · unruffled · imperturbable · placid · tranquil · self-possessed
calmest
Superlative of tranquil
- collectedCalm and self-possessed
- unflappableImpossible to disturb
- poisedCalm and controlled
serene · level-headed · unfazed · stoic · unruffled · imperturbable · placid · tranquil · self-possessed · nonchalant
coldest
Most lacking heat
- iciestMost frozen or unfriendly
- frostiestMost covered in ice crystals
- frigidExtremely and intensely cold
freezing · glacial · arctic · polar · wintry · nippy · brisk · bitter · numbing · shivering
hippest
Most culturally current
dopest · flyest · chicest · sharpest · snazziest · sleekest · swankiest · edgiest · raddest · illest
- cooled offLost warmth or temper
- water coolerChilled beverage dispenser
- cooled downReduced in temperature
- swamp coolerMoisture-based air cooling device
- wine coolerFruity alcoholic beverage
- water cooler talkInformal workplace chatter