drab: [16] Drab is a variant of the now obsolete form drap, which was borrowed from Old French drap ‘cloth’ (source also of English drape, draper, and trappings). It was originally a noun meaning ‘cloth’ in English too, but the beginnings of its transition to the modern English adjective meaning ‘faded and dull’ can be seen in the 17th century.
The word came to be used particularly for natural undyed cloth, of a dull yellowish-brown colour, and hence for the colour itself (an application best preserved in the olive-drab colour of American service uniforms). The figurative development to ‘dull and faded’ is a comparatively recent one, first recorded a little over a hundred years ago. => drape, trappings
