up ‧ on S2 W1 /əˈpɒn $ əˈpɑːn/ BrE AmE preposition formal
[ Date: 1100-1200 ; Origin: up + on ]
1 . used to mean ‘on’ or ‘onto’:
an honour bestowed upon the association
We are completely dependent upon your help.
Brandon threw him upon the ground.
2 . if a time or event is upon you, it is about to happen:
Winter is almost upon us.
3 . layer upon layer/mile upon mile etc used to emphasize that there are a lot of layers, miles etc:
mile upon mile of golden sand
⇨ once upon a time at ↑ once 1 (14), ⇨ take it upon yourself to do something at ↑ take 1 (27)