American Standard Version
They are vanity, a work of delusion: in the time of their visitation they shall perish.

Berean Study Bible
They are worthless, a work to be mocked. In the time of their punishment they will perish.

Douay-Rheims Bible
They are vain works, and worthy to be laughed at, in the time of their visitation they shall perish.

English Revised Version
They are vanity, a work of delusion: in the time of their visitation they shall perish.

King James Bible
They are vanity, the work of errors: in the time of their visitation they shall perish.

World English Bible
They are vanity, a work of delusion: in the time of their visitation they shall perish.

Young's Literal Translation
Vanity are they -- work of errors, In the time of their inspection they perish.

Jeremiah 51:18 Additional Translations ...