a ‧ me ‧ li ‧ o ‧ rate /əˈmiːliəreɪt/ BrE AmE verb [transitive]
[ Date: 1700-1800 ; Origin: meliorate 'to ameliorate' (16-20 centuries) , from Late Latin , past participle of meliorare , from Latin melior 'better' ]
formal to make a bad situation better or less harmful SYN improve :
It is not clear what can be done to ameliorate the situation.
—amelioration /əˌmiːliəˈreɪʃ ə n/ noun [uncountable]