IPA: /ˈʃɔːrtfɔːl/
KK: /ˈʃɔrtˌfɔl/
A situation where there is not enough of something that is needed or expected.
The company faced a shortfall in revenue this quarter due to lower sales.
Shortfall → It is formed from "short" (from Old English *sceort*, meaning not long or lacking) and "fall" (from Old English *feallan*, meaning to fall or drop). The word "shortfall" refers to a situation where there is a deficiency or a falling short of a required amount.
Think of something that is 'lacking' ('short') and 'dropping' ('fall') below what is needed — that's what a shortfall means.