Sub-Zero is a 8 letter English word. It's valid Scrabble word worth 5 points. It's valid Words with friends word worth 7 points.
You can make 144 anagrams from letters in sub-zero (-beorsuz).
During the day the heat would boil eggs, and at night the sub-zero cold cracked great scales off the granite boulders.
The Wing Commander stiffened and snorted like a Merlin backfiring on a sub-zero morning.
They were all bundled in heavy garments, for the temperature of Callisto, never high, frequently drops to sub-zero readings.
The sub-zero temperature of Meta's voice left no doubt as to what she wanted to do with her.
We have since found that it can and does heat the entire house even at sub-zero temperatures.