IPA: /ˈæpɪtənsɪ/
KK: /ˈæpɪtənsɪ/
A strong and fixed desire for something.
His appetency for knowledge drove him to read every book he could find.
Appetency is formed from "appetere" (meaning to strive for or seek) and the suffix "-cy" (indicating a state or condition). The word describes the state of having a strong desire or inclination towards something.
Think of 'striving for' something ('appetere') to remember that 'appetency' means a strong desire or inclination.