upon
prepositionformal/ɐ.kwɐ̃.du/low
a·quan·do
Definition
Preposition indicating temporal coincidence; at the time of, on the occasion of.
Upon his visit, the museum was closed.
The contract was signed upon the foundation of the company.
Common collocations
upon theupon his/her
Etymology
Do latim 'ad quando' (no tempo em que).