Webster's Revised Unabridged Dictionary · 1913

Aptitude

Aptitude ({not transcribed}) , noun

[French aptitude, Late Latin aptitudo, from Latin aptus. See Apt, and compare Attitude.]

1.
A natural or acquired disposition or capacity for a particular purpose, or tendency to a particular action or effect; as, oil has an aptitude to burn.
He seems to have had a peculiar aptitude for the management of irregular troops. — Macaulay
2.
A general fitness or suitableness; adaptation.
That sociable and helpful aptitude which God implanted between man and woman. — Milton
3.
Readiness in learning; docility; aptness.
He was a boy of remarkable aptitude. — Macaulay