whereof

7 9.9

About what was just mentioned

adverb
/ˈwɛrˌɔf/

Archaic

: de lo cual

She is insightful and she knows whereof she speaks.
whereof they speak
know whereof

So Jim Cramer knows whereof he speaks.

Examples

Do we know whereof we speak?

Blog text (28)
So Jim Cramer knows whereof he speaks.

YaleCourses
IN WITNESS WHEREOF, the undersigned Plenipotentiaries have signed this Treaty.

Blog text (7)
In witness whereof, I ask these same SEC questions. I realized that there is a lot of confusion concerning SEC regulations versus private lending.

Blog text (23)
In testimony whereof, I have hereunto set my hand and caused the seal of the United States to be affixed.

Blog text (23)
I believe that creative writing courses should only be taught by those who have labored in the trenches of the publishing or screenwriting business and thus know whereof they speak.

Academic text (2009)
"Clearly they know whereof they speak."
So Jim Cramer knows whereof he speaks.
In witness whereof, we have hereunto subscribed our names.

Synonyms

thereof

vswhereof

Formal

74 7.0

About the thing just mentioned

refers to what or about which rather than to a specific named thing

Surface Forms

whereof positive

Morphology

whereof = where (semi-transparent) = of + where

Formed from the clear components 'where' + 'of' with meaning 'of which', but the fused, formal/archaic usage may be unfamiliar to many learners. [Postprocessing: moved 'of' from base_words to prefix]

Etymology

Whereof is formed by the everyday words where and of, and it originally meant 'of which' or 'about which'. That's why whereof is a formal or old-fashioned way to point back to something just mentioned.