Cease, finish, end, stop, stay, or disembark. Those words are the opposites of embark.
disembark
disembark, stay
Embark on an adventure.
The past tense of embark, meaning to board transportation (as on a journey), would be similar to the use of "coming" and "going", and would have the counterpart debarked or disembarked. (for aviation, having left transport is "deplaned") This form could also have the antonym "stayed" if it implied one never left. *"Embarked" is used rarely as an adjective meaning onloaded or put in transport, so could have the antonym "ashore" or "unshipped".
I embark on a journey.
That could be "embark" as to embark an airplane or to "continue" .
It means to get on a ship.
The antonym of the word 'synonym' is 'antonym'.
As we embark upon this dangerous voyage, let us consider our advantages.
An antonym means "opposite". So an antonym for the word synonym is antonym.
Embark
Europeans first embark on exploration to the East as they looked for trade routes