The Collaborative International Dictionary of English v.0.48:
Portly \Port"ly\, a. [From Port demeanor.] 1. Having a dignified port or mien; of a noble appearance; imposing. [1913 Webster] 2. Bulky; corpulent. "A portly personage." --Dickens. [1913 Webster]WordNet (r) 3.0 (2006):
portly adj 1: euphemisms for `fat'; "men are portly and women are stout" [syn: portly, stout]