plāˈna(a)ˌrizəm noun
or plein·air·isme plenerēs(m ə ), -ēz(m ə ), -s(mə), -z(mə)
( -s )
Etymology: French pleinairisme, from plein air + -isme -ism
: the study, action, or product of plein air painting ; specifically : the plein air art movement in France