IPA: /ˈɡlædnəs/
KK: /ɡlædnəs/
The state of feeling happy or joyful.
Her face was filled with gladness when she received the good news.
Gladness → It is formed from "glad" (from Old English *glæd*, meaning joyful or bright) and "-ness" (meaning the state or quality of). The word "gladness" refers to the state of being joyful or happy.
Think of the word 'glad' which means joyful, and remember that 'gladness' is the state of being joyful.