1) A term used to describe one's body part which has become excessively cold.
2) Very cold.
After holding a cold drink for several minutes:
"My hand is so sub-zero right now."
An expensive brand of refrigerators for the flashy/throw-money-in-toilet type. It's not the best brand but somehow gets probably the most money.
"Hey, check out my Sub-Zero. It's compensation for my lack of manhood, just like my gun collection."