re ‧ gress /rɪˈɡres/ BrE AmE verb [intransitive]
[ Date: 1500-1600 ; Language: Latin ; Origin: past participle of regredi 'to go back' ]
technical to go back to an earlier and worse condition, or to a less developed way of behaving OPP progress :
The patient had regressed to a state of childish dependency.