IPA: /ʌnˈdreɪnd/
KK: /ʌnˈdreɪnd/
Describing something that has not been emptied of liquid, especially water.
The undrained land was soggy and difficult to walk on.
Undrained → It is formed from the prefix "un-" (meaning not) and the root "drain" (from Old French *drainer*, meaning to draw off water). The word "undrained" means not having been drained or not having had water drawn off.
Think of 'not' ('un-') having 'water drawn off' ('drain') — that's why undrained means there is still water present.