Apropos /(ăp"rō̇*pō`)/

Ap·ro·pos

Apropos

a. & adv.
  1. Opportunely or opportune; seasonably or seasonable.
    A tale extremely apropos.
  2. 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.