cabinet (n.)

1540s, "secret storehouse, treasure chamber; case for valuables," from Middle French cabinet "small room" (16c.), diminutive of Old French cabane "cabin" (see cabin); perhaps influenced by (or rather, from) Italian gabbinetto, diminutive of gabbia, from Latin cavea "stall, stoop, cage, den for animals" (see cave (n.)).

Meaning "case for safe-keeping" (of papers, liquor, etc.) is from 1540s, gradually shading to mean a piece of furniture that does this. Sense of "private room where advisers meet" (c. 1600) led to modern political meaning "an executive council" (1640s); perhaps originally short for cabinet council (1620s); compare board (n.1) in its evolution from place where some group meets to the word for the group that meets there. From 1670s also "building or part of a building set aside for the conservation and study of natural specimens, art, antiquities, etc."