In the past five years, I've heard hundreds of references to President
Clinton's comment, I believe made during a legal proceeding, "it
depends on what is is." My question is, What was the "is" that he was
referencing? What is the context of this remark? Indeed, does the
Oxford English Dictionary provide more than a single definition of
"is"?

Clinton's famous statement quibbling about the meaning of the word
'is' was made on August 17, 1998, during his testimony before of the
federal grand jury that was investigating his alleged dalliance with
Monica Lewinsky. The videotaped testimony was released to the media on
September 21, 1998.

Here you'll find the actual quote, with a summary of the context:

"Take, for example, the exchange in which President Clinton first
contended that, since he had no sexual intercourse with Monica
Lewinsky, he had no 'sexual relations' with her.

He was reminded that, during the deposition, his lawyer, Robert
Bennett, referring to Lewinksy's affidavit, said, 'There is absolutely
no sex of any manner, shape or form.' Oh, well, said Clinton, he was
too preoccupied to correct Bennett.

Anyway, Clinton argued, Bennett was speaking in the present tense. 'It
all depends,' said the president, 'on what the meaning of the word
'is' is. If the -- if he -- if 'is' means is and never has been, that
is not -- that is one thing. If it means there is none, that was a
completely true statement....

'Now if someone had asked me on that day, 'Are you having sexual
relations with Ms. Lewinksy?' That is, asked me a question in the
present tense, I would have said, 'No.' And it would have been
completely true.'

'Do you mean today,' the incredulous prosecutor asked, 'that because
you are not engaging in sexual activity with Ms. Lewinsky during the
deposition that the statement of Mr. Bennett might literally be true?"

Reason Online
http://reason.com/glassman/092298.shtml

On this page you can read the transcript in which the quote appears:

Jurist: The Law Professors' Network
http://jurist.law.pitt.edu/transcr.htm

Google search strategy:

Google Web Search: "clinton" + "lewinsky" + "meaning of the word is"
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=clinton+lewinsky+%22meaning+of+the+word+is

Regarding the matter of the Oxford English Dictionary, I consulted the
OED, which I keep near at hand in my office, and found these
definitions of 'is':

Is (iz) v. 3 sing. pres. indic. of vb. BE, q.v.
Is, obs. form of HIS, ICE, YES.
Is- see ISO-
-is (-ys) a frequent ME and esp. Sc. variant of the grammatical
inflexion -es, -s, of the genitive sing., and the pl. of sbs., and of
the 3rd pers. sing. of verbs. In MSS, sometimes treated as a separate
word or element, esp. in genitive sing., where prob. it was often
confounded with the poss. pron. his (is).
-is northern and esp. Sc. f. -ISH, q.v.

Perhaps Mr. Clinton's pondering of the meaning of the word 'is' was a
philosophical exercise rather than a lexical one. In any case, this
Clintonian utterance became one of only three Clinton quotes to make
the latest edition of "Bartlett's Familiar Quotations."

I hope this information is useful. If anything is unclear, or if a
link does not function, please request clarification; I'll gladly
offer further assistance before you rate my answer.

Best regards,
pinkfreud

Thank you very much for the five-star rating! I'd like to correct an
error in my answer: in the first sentence, the phrase "during his
testimony before of the
federal grand jury" should be "during his testimony before the federal
grand jury."

But that may depend on the meaning of 'of'. ;-)

I would like to purchase the OED. Which format of the OED do you use?

Thanks,

Todd

I have a 1981 "compact edition" of the OED, which contains the
complete text of the original 20-volume OED in two huge, heavy
volumes. The way they were able to do this was to print the text
"micrographically." A magnifier is provided with the boxed set so that
the text may be read.

More info here:

http://www.oup-usa.org/isbn/0198612583.html

As soon as I can afford it, I plan to order the CD-ROM edition of the
OED II. If I were planning to buy my first OED, I would go with the
CD-ROM. In my view, the ability to conduct searches across the full
OED text gives this the edge over printed versions.

Here's some information on the CD-ROM version:

http://www.oed.com/public/publications/cdrom_v3.htm