Dutch word behoorlijk comes from Dutch behoren, Dutch -lijk (-able. -ly, -al, -ous.)

Detailed word origin of behoorlijk

Dictionary entry	Language	Definition
behoren	Dutch (nld)	(intransitive) to befit, behoove. (intransitive) to belong [+ tot (to)] (be accepted in a group).
-lijk	Dutch (nld)	-able. -ly, -al, -ous.
behoorlijk	Dutch (nld)	Quite Reasonable, fitting, proper.

Words with the same origin as behoorlijk