Can compound words like 「外食」be considered as a morpheme? According to Wikipedia, > In linguistics, a morpheme is the smallest grammatical unit in a language. In other words, it is the smallest meaningful unit of a language. By that definition, do you think a compound word like should be considered as a morpheme, or should it be further divided into and because each of them carry their own meaning?

Not sure I should answer this, but it is related to Japanese after all, so I'll go ahead.

So, by definition - no. is a lexeme that consists of more than one stem. That alone is enough to say that it cannot be a morpheme. To elaborate a bit more, both and are actually unbound morphemes (they appear not only as part of larger words), meaning that it's impossible for a combination of the two to be a single morpheme. One might even go as far as say that there are no bound morphemes in Japanese that have a Kanji writing, though I'm not an expert in Japanese linguistics, so take that statement with a grain of salt. An example of a bound morpheme in Japanese, by the way, would be the modifier (the one you see in ).