Ad hoc, ad hock, add hoc, add hock?

Which is correct?
You can customize an _________ report on the fly to find the answer to a question that isn’t a part of regular reporting.
a. ad hoc
b. ad hock
c. add hoc
d. add hock

Answer: a.

Explanation:
Ad hoc is a Latin phrase meaning “for this.” We use it to refer to one-off, spontaneous events, like ad hoc analysis or an ad hoc network.

Most people that are using this phrase spell it correctly. Google survey says:

ad hoc: 29,000,000
ad hock: 30,600
add hoc: 30,500 results
add hock: 3,630 results

Nevertheless, I was surprised by the number of “ad hocks” and “add hocks” in otherwise well-written documents. Not quite so surprised, though, to notice that most seemed to be IT-related.

See a Latin phrase cheatsheet.

Test your knowledge of common Latin phrases with our quiz.

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