A flashy and sometimes un-tasteful piece of clothing , usually a really bad Hawaiian short-sleeve button-up.

Could also apply to someone who doesn't seem to look good in modern fashion or has retired to Florida.
Tom- Jeez Mat did you see Jake wearing that ugly shirt?

Mat- Yea that's such a Brett Shirt, he should hire a personal clothing coach.
by The Space Jew April 21, 2019
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