roundabout vs indirect

roundabout is a noun but indirect is not a noun.

Word	Noun	Adjective	Verb	Adverb
roundabout	Yes	Yes	No	No
indirect	No	Yes	No	No

roundabout (noun)	indirect (noun)
a road junction at which traffic streams circularly around a central island
a large, rotating machine with seats for children to ride on for amusement

roundabout (adjective)	indirect (adjective)
deviating from a straight course	not direct in spatial dimension; not leading by a straight line or course to a destination
marked by obliqueness or indirection in speech or conduct	extended senses; not direct in manner or language or behavior or action
	descended from a common ancestor but through different lines
	having intervening factors or persons or influences
	not as a direct effect or consequence