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to lean over (and cover with one's body); to bend over (someone); to (stand tall and) lean on (someone)
to weigh on one; to bear (heavily) on one; to lie on one
強風がテントにのしかかってきた。
Strong winds bore down on the tent.
重い責任がのしかかる。
Heavy responsibility weighs on me.
借金がのしかかっている。
Debt is weighing on me.