1. [n]  a person who is recovering from illness
2. [adj]  returning to health after illness or debility; "convalescent children are difficult to keep in bed"
3. [adj]  of or for or relating to convalescence or convalescents; "convalescent home"

CONVALESCENT is a 12 letter word that starts with C.

1. \Con`va*les"cent\, a. [L. convalescens, -entis, p.
   pr.: cf. F. convalescent.]
   1. Recovering from sickness or debility; partially restored
      to health or strength.
   
   2. Of or pertaining to convalescence.
   
   

2. \Con`va*les"cent\, n.
   One recovering from sickness.