'Riant' definitions:

Definition of 'riant'

adjective

Showing or feeling mirth or pleasure or happiness; "laughing children" [syn: laughing(a), riant]

From: GCIDE

Riant \Ri`ant"\, a. [F. riant, p. pr. of rire to laugh, L. ridere.] Laughing; laughable; exciting gayety; gay; merry; delightful to the view, as a landscape. [1913 Webster]
In such cases the sublimity must be drawn from the other sources, with a strict caution, howewer, against anything light and riant. --Burke. [1913 Webster]