IPA: /ʌnˈdrɔːn/
KK: /ʌnˈdrɔn/
Not pulled or stretched; in a state where something is open or has not been taken out, such as curtains or money.
The curtains were undrawn, allowing sunlight to fill the room.
Undrawn is formed from "un-" (meaning not) and "drawn" (the past participle of "draw", which comes from Old English "dragan", meaning to pull or drag). The word "undrawn" means not pulled or not drawn out.
Think of 'not' ('un-') having something 'pulled out' ('drawn') — that's why undrawn means something that hasn't been pulled out.