Dedushka means grandfather in Russian. The word dedushka is also used to talk about old men in general.
In Russian alphabet, it’s written де́душка.
Possible variations of dedushka:
– дед [dyed] (a bit rude)
– деду́ля [dye-dú-lya] (loving)
An old man can be also called стари́к [sta-réek] or старичо́к [sta-ree-chók], from the word ста́рый (old). In this case it’s just a random old man and not a grandpa.