We don't have synonyms for housesit yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are houses, house-sit and house sit.
(v) :
Alternative form of house-sit. [(ambitransitive) To live temporarily in someone else's home, or to attend it regularly, for the purpose of protecting and tending to it in the owner's or tenant's absence.]
(v) :
Alternative form of house-sit. [(ambitransitive) To live temporarily in someone else's home, or to attend it regularly, for the purpose of protecting and tending to it in the owner's or tenant's absence.]