IPA: /ˈɡrætɪfaɪɪŋli/
KK: /grætɪfaɪɪŋli/
In a way that brings pleasure or satisfaction.
She smiled gratifyingly when she received the good news.
Gratifyingly → It is formed from "gratify" (from Latin *gratificare*, meaning to please or give pleasure) and the suffix "-ingly" (meaning in a manner that). The word "gratifyingly" means in a manner that gives pleasure or satisfaction.
Think of the word 'gratify' which means to please, and remember that 'gratifyingly' describes doing something in a way that brings pleasure.