attire

 
Pronunciation: /əˈtʌɪə/
formal or literary

noun

[mass noun]
  • clothes, especially fine or formal ones: the usually sober attire of British security service personnel

verb

(be attired)
  • be dressed in clothes of a specified kind: Lady Agatha was attired in an elaborate evening gown (as adjective, with submodifier attired) stylishly attired teenagers in stonewashed jeans

Origin:

Middle English: from Old French atirier, atirer 'equip', from a tire 'in order', of unknown origin