In the Unfinished Tales, the chapter The Drúedain and its Notes (No. 6 to be specific) gives a definition of Drúwaith as “the wilderness of the Drû-folk”.
In the Complete Guide to Middle Earth, Enedwaith and Forodwaith are defined as “Middle Folk” and “North People”, respectively.
The question is, what is the true definition of the suffix “-waith”, is it wilderness (which I think makes more sense) or is it People or Folk?
Ruth S. Noel's excellent The Languages of Middle-earth has "waith" as people or folk, and refers to the glossary of Elven language terms from The Silmarillion as its source, so I'd go with the "people/folk" meaning.