Definition of deforming:
(v) :
(transitive) To change the form of (something), usually thus making it disordered or irregular; to give (something) an abnormal or unusual shape.
(v) :
(transitive) (also figuratively) To change the look of (something), usually thus making it imperfect or unattractive; to give (something) an abnormal or unusual appearance.
(v) :
(transitive) (engineering, physics) To alter the shape of (something) by applying a force or stress.
(v) :
(transitive) To mar the character or quality of (something).
(v) :
(intransitive) To become changed in shape or misshapen.
(adj) :
(obsolete except poetic) Having an unusual and unattractive shape; deformed, misshapen; hence, hideous, ugly.