noun
grandfather; granddad
Familiar or casual word for one's grandfather. It is less polite and softer than some contexts allow; おじいさん or 祖父 is safer in polite speech. May also follow a name as a familiar honorific.
See also: お祖父さん
夏休みにじいさんの家へ行った。
I went to my granddad's house during summer vacation.
うちのじいさんは毎朝散歩している。
My granddad takes a walk every morning.
noun
old man; elderly man; male senior citizen
Casual, familiar, and sometimes blunt way to refer to an elderly man. With a name, as in 佐藤じいさん, it can sound rustic or familiar rather than formally polite.
See also: 爺ちゃん
公園のベンチにじいさんが一人座っていた。
An old man was sitting alone on a bench in the park.
佐藤じいさんは村でいちばんの長老だ。
Old Mr. Sato is the senior elder of the village.