1. 
[syn: button-down, buttoned-down, conservative]
The Collaborative International Dictionary of English v.0.48:
buttoned-down \buttoned-down\ adj.
   conservatively formal and businesslike in dress and manner.
   Syn: button-down, conservative.
        [WordNet 1.5]
              a colorful character in the buttoned-down,
              dull-gray world of business.        --Newsweek
WordNet (r) 3.0 (2006):
buttoned-down
    adj 1: unimaginatively conventional; "a colorful character in
           the buttoned-down, dull-grey world of business"- Newsweek
           [syn: button-down, buttoned-down, conservative]