(historical) A color print produced by chromolithography.
The neglected warehouse turned out to be a treasury of calendar art from the 1930s through the 1970s, years when chromo art calendars were a major advertising medium, a vehicle for national pride, and a fixture in nearly every home, business, and school. 1999 February 19, Deanna Isaacs, “On Exhibit: a treasure trove of Mexican pop art”, in Chicago Reader:
All Nature is smiling, in fact, with one large, comprehensive smile, exactly like a first-class PRANG chromo with a fresh coat of varnish upon it. 1870, Various, Punchinello Vol. 1, No. 21, August 20, 1870:
It was manifest that we all felt that we ought to send the poor shoemaker SOMETHING. There was long and thoughtful discussion of this point; and we finally decided to send him a chromo. 1883, Mark Twain (Samuel Clemens), Life on the Mississippi:
That dried-up lady snob lived behind lace curtains all her life. She's of no more importance than a chromo. 1970, John Glassco, Memoirs of Montparnasse, New York, published 2007, page 81:
(not-comparable) Of or relating to the chromodomain, a protein structural domain associated with chromatin production
To determine whether the conserved domains, the chromo, SET, and cysteine-rich regions, were also critical for Clr4 HMTase activity, we tested mutant Clr4 proteins for HMTase activity. 2001 April 6, Jun-ichi Nakayama et al., “Role of Histone H3 Lysine 9 Methylation in Epigenetic Control of Heterochromatin Assembly”, in Science, volume 292, number 5514, →DOI, pages 110–113:
HP1 shares an ~50-amino acid NH 2 -terminal sequence motif, the chromo domain, with polycomb, an important regulatory gene that functions in the stable repression of homeotic genes during Drosophila development (28 ). 1998 April 24, Angus I. Lamond, William C. Earnshaw, “Structure and Function in the Nucleus”, in Science, volume 280, number 5363, →DOI, pages 547–553: