Taco Tuesday UK /ˌtækəʊ ˈtjuːzdeɪ/US /ˌtɑkoʊ ˈt(j)uzˌdeɪ/ noun1 •(US) A Tuesday when Mexican food is served, especially tacos, chiefly in the evening and originally and especially in a restaurant as a promotion.TACO TUESDAY / Stop in on Taco Tuesday (tomorrow) / You'll get 3 Tacos for $1 plus a FREE COKE — 1973 formsTaco Tuesdays