There are various synonyms for the phrase "reduced in health." Some possible options include "ailing," "ailing health," "ailing state," "ailing condition," "weakened," "weakened health," "debilitated," "frail," "sickly," "unwell," "ailing fitness," "unsound," "unhealthy," and "feeble." These terms all express a decline in physical or mental wellbeing, indicating a state of reduced strength or vitality. Depending on the specific context, one of these synonyms may be more appropriate than the others. Regardless of the word choice, the underlying implication is that the person in question is in a state of ill health that requires attention and care.