"Gradual transition" refers to a slow and step-by-step change from one state or condition to another. It means that the shift or transformation takes place over a period of time, rather than happening suddenly. Full definition
Active recovery is a technique that allows for a more gradual transition from exercise to rest, with low - intensity exercise replacing or supplementing the traditional approach of passive recovery. (mindbodygreen.com)
It's a very gradual transition between shallow and deep. (sonofabea.ch)
A more gradual transition in other countries from producing for export to feeding themselves need not entail this suffering. (religion-online.org)