Definition of "camouflage"

Earless ghost swift moths become “invisible” to echolocating bats by forming mating clusters close […] above vegetation and effectively blending into the clutter of echoes that the bat receives from the leaves and stems around them. Many insects probably use this strategy, which is a close analogy to crypsis in the visible world—camouflage and other methods for blending into one’s visual background.

2013 May-June, William E. Conner, “An Acoustic Arms Race”, in American Scientist, volume 101, number 3, pages 206–7

THE CONCISE ENCYCLOPAEDIA OF WORLD RAILWAY LOCOMOTIVES. Edited by P. Ransome-Wallis. Hutchinson. 50s.A gaudy jacket, remarkably out of keeping with the contents, camouflages the weightiest and meatiest work on a railway topic since the war.

1960 January, “New reading on railways”, in Trains Illustrated, page 26

Elegant brick and stone buildings, with iron and glass canopies and decorative wooden scalloping and fencing—all evidencing care on the part of the architect to produce a pleasing, well-planned building—were submerged beneath a profusion of ill-conceived additions and camouflaged by vulgar paint schemes; and the original conception was lost.

1962 October, Brian Haresnape, “Focus on B.R. passenger stations”, in Modern Railways, pages 250–251