IPA: //ˈbɜːɡlərɪəsli//
KK: /ˈbɜrɡlərɪəsli/
In a manner that relates to stealing or breaking into a place.
The thief moved burglariously through the darkened house, careful not to make a sound.
Burglariously → It is formed from "burglar" (from Old French *burglar*, meaning a thief who breaks into a house) and the suffix "-iously" (meaning in a manner of). The word "burglariously" means in a manner characteristic of a burglar, typically involving theft or breaking and entering.
Think of a burglar acting 'in a manner of' ('-iously') a thief ('burglar') — that's why burglariously describes actions typical of a burglar.