Anyone who attempts to quote the definition of the word "word" as justification for inclusion of their word has committed a sin of logic, instantly loses the debate they are engaged in, and requires no further response other than notification of this law.
"Word" is indeed defined (at the moment of writing) as
- "A distinct unit of language (sounds in speech or written letters) with a particular meaning, composed of one or more morphemes, and also of one or more phonemes that determine its sound pattern."
However, neither does that imply that any unit of language fitting that description is a member of a particular language, nor does it suggest that linguistic merit, widespread use and idiomaticity are not components of conveying a meaning. Defining "word" at someone is a red herring fallacy; it stands in for an actual argument for the merit of a particular word being attested as such.