MEANING: adjective:
1. Conservative, unimaginative, conventional, staid, repressed, etc.
2. Relating to a collar that can be fastened to the garment.
3. Relating to a garment having such a collar or having buttons from the collar to the waist.

ETYMOLOGY: From the association of a button-down shirt with people having such an outlook. Earliest documented use: 1883. The term also appears in the form buttoned-down.

BUST ON DOWN - what's covered by a strapless gown

BUTT ON DAWN - hit with your head the moment the sun rises

BUT TEN-DOWN - I've solved everything from one-down to nine-down...