vedensä
Vedensä is a Finnish grammatical form built from the noun vesi (water). It represents the third-person possessive construction meaning “his/her/its own water.” The form is created by attaching the possessive suffix -nsä to the stem vesi, yielding vedensä. This suffix pattern is part of standard Finnish possessive morphology, where the third-person singular possessive suffix marks ownership by a third person.
In use, vedensä functions as a possessive determiner/pronoun embedded with the noun, indicating water that belongs
The form is most common with the word vesi due to its monosyllabic, vowel-heavy structure, but Finnish
See also: vesi, veden, vettä, possessive suffixes in Finnish grammar. Further reading can include Finnish grammar