physically weak or sickly child
Refers to a child who is constitutionally frail or in poor health. Often used in medical, educational, or social welfare contexts.
Special health management is necessary for physically weak children.
When he was little, he was treated as a sickly child.
虚弱体質 describes a constitutional weakness or frail disposition, not limited to children.
Compound of 虚弱 (physically weak) and 児 (child). The exact historical derivation is uncertain, but the term is conventionally used in medical and social contexts.