na-adjective, noun
in sound health; free from illness
Describes a state of good health without disease. Often used in set phrases like 無病息災.
彼は無病で、一度も入院したことがない。
He is in sound health and has never been hospitalized.
無病息災を願って神社にお参りした。
I visited the shrine to pray for good health and freedom from illness.
健康 is the common word for 'health' or 'healthy', while 無病 specifically emphasizes the absence of disease.
Compound of 無 (mu, 'without') and 病 (byō, 'illness').