Upkeep is the cost and work of keeping something in order. The upkeep of the house, high upkeep, pay for the upkeep.
It is the ongoing cost rather than the purchase, and it is what people underestimate when buying anything large — a boat, a horse or a listed building. It is a mass noun with no plural and takes of.
1nounupkeepThe cost and work of keeping something in order.
“The upkeep of a big garden takes up most of my weekends.”
upkeep is a cost.
Up plus keep, from the nineteenth century.
From up + keep.
Etymology from Wiktionary, CC BY-SA