adjective. Fitting and to the point. synonym: relevant.

adverb. At an appropriate time; opportunely.

adverb. By the way; incidentally.

preposition. With regard to; concerning.

. To the purpose; opportunely; seasonably.

2. With reference or regard; in respect: followed by of.

. With reference to that (a thing just mentioned); by the way: used absolutely, to introduce an incidental observation.

Opportune; seasonable; to the purpose; pertinent; happy: as, an apropos remark.

noun. Pertinency.

Opportunely or opportune; seasonably or seasonable.

By the way; to the purpose; suitably to the place or subject; -- a word used to introduce an incidental observation, suited to the occasion, though not strictly belonging to the narration.

adjective. Of an appropriate or pertinent nature.

adjective. by the way, incidental.

preposition. Regarding or concerning.

adverb. By the way.

adverb. Timely; at a good time.

adjective. of an appropriate or pertinent nature

adverb. at an opportune time

adverb. introducing a different topic; in point of fact

"Great tip for beginners and terminal hackers alike, and apropos is installed on a wide number of Linux distros and other terminals."

malapropos  

apposite  apt  pertinent  

apropos of   apropos of nothing  

Au  Beau  Bio  Bo  Bordeaux  

a propos  about  ad rem  adapted  admissible