noun which may take the genitive case particle 'no', prefix
ultra-low; very low; hyper-; infra-
Prefix-like element used in technical and descriptive compounds to mean extremely low in height, temperature, frequency, etc. Not a standalone word; always attaches to another noun.
It needs to be stored at ultra-low temperatures.
Ultra-low frequency sounds are inaudible to humans.
ultra-low price; extremely low cost
ultra low frequency
ultra-low interest rates
Compound of 超 (ultra-, super-) and 低 (low).