Below zero is a term used to describe temperatures that are lower than 0 degrees Celsius or 32 degrees Fahrenheit. The crossword solutions for this term are OPER (4 letters), ELEVS (5 letters), FRIGID (6 letters), NEGATIVE (8 letters), and NEG (3 letters). OPER stands for 'Operating Temperature', ELEVS stands for 'Elevated Temperatures', FRIGID means 'very cold', NEGATIVE is an antonym of positive, and NEG is a shortened version of the word NEGATIVE.