undirty adjective 1verb 1forms 5 adjective1 •Not dirty.It is particularly unfair for baking powder manufacturers to seek to pervert the truth, or prejudice the ignorant or unwary by statements that it is either harmful or undirty. — 1886 verb1 •To make not dirty.Cleaning Clothes is our business and the dirtier they get, the more we enjoy undirty-ing them; the bigger the job, the more spectacular the result. — 1950 formsundirtied · undirtying · undirties · undirtier · undirtiest