retro

Etymology

Borrowed from French rétro, ultimately from Latin retro.

adj

1. Of, or relating to, the past, past times, or the way things were.
   Scientists say that while the public may think of the moon as a problem solved and a bit retro – the place astronauts visited a half-dozen times way back before Watergate and then abandoned with a giant "meh" from mankind – in fact, lunar studies is a vibrant enterprise that is yielding a wealth of surprises. 7 September 2014, Natalie Angier, “The Moon comes around again [print version: Revisiting a moon that still has secrets to reveal: Supermoon revives interest in its violent origins and hidden face, International New York Times, 10 September 2014, p. 8]”, in The New York Times
2. Affecting things past; retroactive, ex post facto.

noun

1. (uncountable) Past fashions or trends.
2. (countable) Abbreviation of retrorocket.
3. (countable) Abbreviation of retrospective.
   Richard Leacock's 1981 film portrait, Louise Brooks, was shown during a retro of Ms. Brooks's films at the Walker Art Center. 1983, Sightlines, volumes 16-17, page 44