A definition in the patent’s specification can be critical in defining the scope of the claims.  According to the patent statute, the claims and specification are directed to a person of ordinary skill in the art, but it is important to remember that the person construing the patent’s claims — typically a Patent Examiner or a Federal District Judge — is usually not a person of ordinary skill in the art.  Thus, a readily understood, non-technical definition may better serve the inventor’s purposes.  Moreover, a simple example may more clearly define the term than any definition.  Such is the case in the Yogi Bear inspired examples of the definitions of “or” and “and” in U.S. Patent No. 9,607,066:

When used herein to join a list of items, ‘or’ denotes ‘at least one of the items,’ but does not exclude a plurality of items of the list. Thus, reference to ‘a picnic basket having cheese or crackers’ describes ‘a picnic basket having cheese without crackers’, ‘a picnic basket having crackers without cheese’, and ‘a picnic basket having both cheese and crackers.’ Finally, when used herein to join a list of items, ‘and’ denotes ‘all of the items of the list.’ Thus, reference to ‘a picnic basket having cheese and crackers’ describes ‘a picnic basket having cheese, wherein the picnic basket further has crackers,’ as well as describes ‘a picnic basket having crackers, wherein the picnic basket further has cheese.’

These examples make the meaning of the terms clear, in language that can be readily understood by anyone.