weak constitution; frail health
Describes a person who is physically weak, gets sick easily, or has low stamina. Often used in medical or everyday contexts.
He has a weak constitution and often catches colds.
I had a frail constitution as a child, but now I'm healthy.
Compound of 虚弱 (weakness, frailty) and 体質 (constitution, physical makeup). The word is a straightforward Sino-Japanese compound.