Lewis & Short

dē-fingo, nxi, 3, v. a., to form, to put in shape, to fashion (very rare; prob. belonging properly to the vulgar lang.; hence in Hor., by way of sarcasm): panem, Cato R. R. 74 and 121.
Sarcast. of coarse poetic description: dum Defingit Rheni luteum caput, * Hor. S. 1, 10, 37.