Abroad, redcoat's movement 100 years ago (3,4)
I believe the answer is:
art deco
'movement 100 years ago' is the definition.
I can't judge whether this defines the answer.
'abroad redcoat's' is the wordplay.
'abroad' indicates anagramming the letters (abroad can mean moving around).
'redcoat' anagrammed gives 'ART DECO'.
Can you help me to learn more?
(Other definitions for art deco that I've seen before include "1920s/1930s style" , "Style of decorative art popular in 1920s and 1930s" , "1920-30s design style" , "style of interior design" , "Old style" .)