How does this definition use "word"? In analytic languages, most words always appear in the same form, so counting them is relatively easy. But for inflected la

How does this definition use "word"? In analytic languages, most words always appear in the same form, so counting them is relatively easy. But for inflected languages, does this require being able to distinguish the roots of words in order to count them accurately? It's not just about the presence or absence of articles and prepositions, but about different declensions of the same word. If this analysis requires knowing that homo, hominis, hominem and homine all refer to the same word and should be counted as one, how does it help with analyzing a text for which we don't know the grammar?