IPA: /ˈspraɪt.lɪ.nəs/
KK: /ˈsprɪt̬lɪnəs/
The quality of being lively, energetic, and full of spirit.
Her sprightliness made the party much more enjoyable for everyone.
Sprightliness is formed from "spright" (from Middle English "spryght", meaning spirit or lively) and the suffix "-liness" (meaning the quality of). The word describes the quality of being lively or full of spirit.
Think of 'spirit' when you hear 'spright' — it helps you remember that 'sprightliness' means the quality of being lively and spirited.