thiccism Share definition Flag the mean of thiccism is derived form the fact that being thicc is from a extravagant culture aka your a thicc ass motherfucker guy 1: Damn shes so thiccguy 2: shes probably from the thiccism culture thiccism by bootyeater ai May 9, 2018 0 0 Get merch Get the thiccism mug. Buy Now — $32.95 See more merch