[じいさん, jiisan](n) (1) (usu. 祖父さん) (See お祖父さん) grandfather (may be used after name as honorific); (2) (usu. 爺さん) male senior-citizen (may be used after name as honorific); (P)[Add to Longdo]
[じいちゃん, jiichan](n) (1) (fam) (usu. 祖父ちゃん) (See 祖父さん) grandfather (may be used after name as honorific); (2) (usu. 爺ちゃん) male senior-citizen (may be used after name as honorific)[Add to Longdo]