degrow

verb2

1. •
   To become smaller; to shrink.

   • They can eat vast amounts when times are good, and can even ‘degrow’ when food is scarce, consuming their own body mass very slowly, with no ill-effects. — 2014
2. •
   To make (something) smaller, to reduce.

   • It seems likely that wealthy countries in Western Europe and North America need to degrow their economies before establishing a steady state. — 2013