Synonyms of onset in English:

onset


See US English definition of onset

See UK English definition of onset

See Spanish definition of llegada

noun

1‘treatment was administered soon after the onset of symptoms’

SYNONYMS
start, beginning, arrival, appearance, first appearance, opening, outset, inception
outbreak, dawn, birth, infancy, genesis, creation, day one, emergence, rise
formal commencement
ANTONYMS

end, termination