muddy taxi Share definition Flag A muddy taxi refers to the act of taking a shit in a taxi, usually after a night of drinking. Jenny was wasted last night but I can't believe she pulled a muddy taxi on the way home from taco bell. muddy taxi by Zuzzy Foeller February 7, 2014 0 0 Get merch Get the muddy taxi mug. Buy Now — $32.95 See more merch