Webster's Revised Unabridged Dictionary · 1913

Diathesis

Diathesis , noun

[New Latin, from Greek {not transcribed}, from {not transcribed} to place separately, arrange; dia` through, asunder + {not transcribed} to place, put.]

(Medicine) Bodily condition or constitution, esp. a morbid habit which predisposes to a particular disease, or class of diseases.