Can an inventor define terms differently from their ordinary meaning?

Yes, an inventor can define terms differently from their ordinary meaning. This concept is known as “lexicography” in patent law. The MPEP explicitly states in MPEP 2173.05(a):

“Consistent with the well-established axiom in patent law that a patentee or applicant is free to be his or her own lexicographer, a patentee or applicant may use terms in a manner contrary to or inconsistent with one or more of their ordinary meanings if the written description clearly redefines the terms.”

However, when using terms contrary to their ordinary meaning:

• The written description must clearly redefine the term.
• The redefinition must put competitors and those skilled in the art on notice of the intended meaning.
• If the meaning is not clear, it may result in a rejection under 35 U.S.C. 112(b) for indefiniteness.

It’s crucial for inventors to be explicit and precise when redefining terms to avoid confusion and potential claim rejections.

To learn more:

• lexicographer
• patent terminology
• claim interpretation
• patent specification
• indefiniteness