Real Dictionary

full dress
uncountable noun: Someone who is in full dress is wearing all the clothes needed for a ceremony or formal occasion.

full dress in American English
formal clothes worn on important or ceremonial occasions; esp., formal evening clothes
noun: the formal attire customarily worn in the evening, usually consisting of black tailcoats and white bow ties for men, and floor-length dresses for women

full dress in British English
noun: a formal or ceremonial style of dress, such as white tie and tails for a man and a full-length evening dress for a woman

full-dress in American English
of or requiring full dress; formal
adjective: formal and complete in all details

full-dress in British English
adjective: appropriate to a public ceremony, a formal dinner, or evening party