IPA: /ˌmoʊ.mənˈtɛr.ə.li/
KK: /ˈmoʊməntˌɛrəli/
For a very short time or just for a moment.
The train will arrive momentarily, so please be ready.
Momentarily → It is formed from "moment" (from Latin *momentum*, meaning a brief period of time) and "-arily" (meaning in a manner relating to). The word "momentarily" means in a manner relating to a brief period of time, or for a moment.
Think of a 'moment' as a brief period of time, and remember that 'momentarily' means something happening for just a moment.