farewell

interj. [ Fare (thou, you) + well. ] Go well; good-by; adieu; -- originally applied to a person departing, but by custom now applied both to those who depart and those who remain. It is often separated by the pronoun; as, fare you well; and is sometimes used as an expression of separation only; as, farewell the year; farewell, ye sweet groves; that is, I bid you farewell. [ 1913 Webster ]

So farewell hope, and with hope, farewell fear. Milton. [ 1913 Webster ]

Fare thee well! and if forever,
Still forever fare thee well. Byron. [ 1913 Webster ]

☞ The primary accent is sometimes placed on the first syllable, especially in poetry. [ 1913 Webster ]