IPA: /ɪnˈfɔːlɪŋ/
KK: /ɪnˈfɔlɪŋ/
Describing something that is moving towards a large celestial body due to gravitational pull.
The infalling matter created a bright light as it approached the black hole.
Infalling is formed from "in-" (meaning into) and "falling" (from the root "fall" which comes from Old English "feallan", meaning to drop or descend). The word describes the action of something that is falling into a place or condition.
Think of something 'falling' ('fall') 'into' ('in-') a certain area or state — that's what infalling means.