convalesce
Concise Oxford English Dictionary © 2008 Oxford University Press:
convalesce /ˌkɒnvəˈlɛs/
▶verb gradually recover one's health after an illness or medical treatment.
– origin C15: from L. convalescere, from con- ‘altogether’ + valescere ‘grow strong’.
'convalesce' also found in these Oxford entries:

