The phrase "decreasing radius" means that something is getting smaller or becoming less round.
Sentences with «decreasing radius»
If you want to rocket out of decreasing radius corners in the hills, what are you doing in a mid-size anyway? (digitaltrends.com)
With modern telescopes, astronomers observing Saturn's rings from Earth can pick out four distinct broad bands, which have been labelled A, B, C and D in order of decreasing radius. (newscientist.com)
Several decreasing radius corners at RMP gave me ample opportunity to work on this. (automobilemag.com)