[ thair-uhv, -ov ]
/ ˌðɛərˈʌv, -ˈɒv /
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of that or it.
from or out of that origin or cause.
Were you ready for a quiz on this topic? Well, here it is! See how well you can differentiate between the uses of "was" vs. "were" in this quiz.
Question 1 of 7
“Was” is used for the indicative past tense of “to be,” and “were” is only used for the subjunctive past tense.

Origin of thereof

before 1000; Middle English therof,Old English thǣrof.See there, of1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What does thereof mean?

Thereof means of, from, because of, or concerning the thing that was just mentioned, as in The warranty covers the device and the parts thereof (translation: The warranty covers the device and the parts of the device).

Thereof is fairly formal. It’s often used in legal language, but it can also be used in everyday speech and writing.

Thereof is perhaps most commonly used in the phrase lack thereof, meaning the lack of the thing just mentioned. This is used in cases in which something is mentioned in a general way but the situation being discussed involves the lack of that thing, as in Most relationship problems are due to communication, or a lack thereof (translation: Most relationship problems are due to communication issues, specifically a lack of communication).

Other common phrases that use the word are combination thereof (meaning a combination of the things just mentioned) and portion thereof (meaning a portion of the things just mentioned).

Example: My research is focused on investigating the cause of the disease and the effects thereof.

Where does thereof come from?

The first records of the word thereof come from before 1000.

There are many similar words based on the combination of the word there and a preposition, each of which has a different meaning, including thereabout, thereabouts, thereafter, thereat, thereby, therefor, therefore, therefrom, therein, thereinafter, thereinto, thereon, thereto, theretofore, thereunder, thereupon, therewith, and therewithal.

Other words are constructed in similar ways, such as whereof, meaning “of what, which, or whom,” as in The person whereof I speak (translation: the person of whom I speak or The person I’m speaking about).

Did you know ... ?

What are some synonyms for thereof?

What are some words that share a root or word element with thereof

What are some words that often get used in discussing thereof?

How is thereof used in real life?

Thereof is fairly formal and is often used in legal language. But it’s not uncommon for it to be used in everyday speech, especially in phrases like a lack thereof or a combination thereof.

Try using thereof!

Is thereof used correctly in the following sentence?

I need to talk to you about your punctuality, or lack thereof.

How to use thereof in a sentence

British Dictionary definitions for thereof

/ (ˌðɛərˈɒv) /

adverb formal
of or concerning that or it
from or because of that
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012