Wiktionary
supersoft
a. 1 Very soft 2 (context astronomy English) Describing astronomical X-rays of very low energy
Wikipedia
Supersoft
Supersoft is a software and computer game developer and publisher founded in England in 1978. It was founded by Peter Calver and Pearl Wellard to develop and publish software primarily for the Commodore PET.
Usage examples of "supersoft".
The walls on the lower level were all soundproofed, but Pet still kept his voice supersoft as he talked.