noun which may take the genitive case particle 'no'
in the hospital; hospitalized
Describes the state of being hospitalized. Often used as a no-adjective modifying nouns (e.g., 入院中の患者).
彼は今、入院中です。
He is currently in the hospital.
入院中の祖母を見舞いに行った。
I went to visit my hospitalized grandmother.
Compound of 入院 (hospitalization) + 中 (in the middle of, during).