Scavenger=Trash pickup
The likely English word is "vulture" (a carnivorous bird renowned as a scavenger).
Thee and thou mean "you" in old english.
tarry means currly in old english
There is no known word "poosk" in Old English. It is most likely not an Old English term.
Scavenger
In Old English they did not use the letter k but the word "cyle" is the Old English word for "cold".
"Schleterkadavski" does not have a specific meaning in English or any known language. It is likely a made-up or coded word for a clue in the scavenger hunt list that participants must decipher or interpret in order to progress in the game.
No
you
Money
An old lady