apropos of

Idioms and Phrases

Concerning, in connection with, as in Apropos of keeping in touch, I haven't heard from her in months . This idiom was a borrowing of the French à propos de (“to the purpose of”) in the 17th century. At first it was used without of and meant “fitting” or “opportune,” as in Their prompt arrival was very appropos . By the 1700s it was also being used with of , as in the current idiom, for “concerning” or “by way of.”