|Origin:||up + on|
up‧on S3 W1 formal
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.
if a time or event is upon you, it is about to happen:
Winter is almost upon us.
used to emphasize that there are a lot of layers, miles etc:
mile upon mile of golden sand