Merriam-Webster Collegiate Dictionary - covert

 I. adjective  Etymology: Middle English, from Anglo-French, past participle of coverir to cover  Date: 14th century  1. not openly shown, engaged in, or avowed ; veiled a ~ alliance  2. covered over ; sheltered  Synonyms: see secret  • ~ly adverb  • ~ness noun  II. noun  Date: 14th century  1.  a. hiding place ; shelter  b. a thicket affording cover for game  c. a masking or concealing device  2. a feather covering the bases of the quills of the wings and tail of a bird — see wing illustration  3. a firm durable twilled sometimes waterproofed cloth usually of mixed-color yarns