IPA: /ˈsteɪdli/
KK: /steɪdli/
In a serious, steady, and respectable way, without excitement or enthusiasm.
She staidly listened to the lecture, showing no signs of boredom or distraction.
Staidly is derived from "staid" (from Middle English "stayed", meaning settled or fixed) and the adverbial suffix "-ly" (meaning in a manner of). The word "staidly" means in a manner that is settled or serious, reflecting a calm and composed demeanor.
Think of someone who is 'settled' and 'fixed' in their demeanor, acting in a serious way — that's what 'staidly' means.