From Wiktionary, the free dictionary
᠊ᡴᡠ • (-ku) (complying with vowel harmony)
- Used to form verbal nouns which denote instruments and utensils, occupation, profession and rank
- ᡶᡠᠰᡠ᠊ (fusu-, “to sprinkle”) + ᠊ᡴᡠ (-ku) → ᡶᡠᠰᡠᡴᡠ (fusuku, “sprinkling can”)