I believe his grandfather was William Denneny, brother to my great-grandfather, Edward Denneny (1845-1897), Co. Cavan>Providence, RI.
from the "Providence (RI) Journal":
>08/22/2002 > >CHARLES E. DENNENY, 86, of Denver Street, a former printer, died Friday at Memorial Hospital of Rhode Island. > >Born in Pawtucket, a son of the late Edward H. and Eliz A. (Murray) Denneny, he was a lifelong resident of the city. > >Mr. Denneny had been a printer at Novelty Press for many years, and later worked at Health Tex, retiring in 1978. > >He leaves two nephews, Michael L. Denneny of New York City and Joseph B. Denneny of Edwardsville, Ill. He was the brother of the late Frederick J. Denneny and Leo M. Denneny. > >The funeral and burial were private. >