This is the 7432nd most frequent Russian word.
гришина
"Гришина" is a Russian surname, the feminine form of "Гришин," derived from the name "Гриша" (Grisha), a diminutive of "Григорий" (Gregory).
Here, 'Гришина' is used as a possessive adjective derived from a personal name, indicating ownership ('Grishina's').
Гришина кошка улеглась на диван.
Grishina's cat lay down on the couch.
In this case, 'Гришина' refers to a person named Grishina, used in nominative case as the subject of the sentence.
Подруга Гришина озадачилась её поступком.
Grishina's friend was puzzled by her act.
Here, 'Гришину' refers to a person named Grishina, but is used in the accusative case as the direct object of the verb.