I. preposition with reference to; concerning • she remarked apropos of the initiative, ‘It’s not going to stop the abuse’.
II. adjective — [ predic.] 1. very appropriate to a particular situation • the song feels apropos to a midnight jaunt.
III. phrases apropos of nothing having no relevance to any previous discussion or situation. • Isabel kept smiling apropos of nothing.
– origin mid 17th cent.: from French à propos ‘(with regard) to (this) purpose’.