'button-down' definitions:

Definition of 'button-down'

(from WordNet)
adjective
Unimaginatively conventional; "a colorful character in the buttoned-down, dull-grey world of business"- Newsweek [syn: button-down, buttoned-down, conservative]
adjective
Of a shirt; having the ends of the collar fastened down by buttons; "Brooks Brothers button-down shirts"

Definition of 'button-down'

From: GCIDE
  • buttoned \buttoned\ adj. furnished with buttons or something buttonlike. Opposite of unbuttoned. [Narrower terms: botonee, botonnee; button-down; closed] [WordNet 1.5]