I find it refered to as both adverb and adjective depending on where I look. I think there's a lot of overlap between those two things though. Probably depends on context. I see niggard itself listed as a verb as well. So which is what seems very dependant on its usage and context.
[ + ] account deleted by user
[ - ] account deleted by user 1 point 4 yearsApr 2, 2021 15:26:24 ago (+1/-0)
[ + ] Roy_Batty
[ - ] Roy_Batty 0 points 4 yearsApr 2, 2021 15:51:32 ago (+0/-0)
[ + ] MrPim
[ - ] MrPim 0 points 4 yearsApr 2, 2021 15:53:44 ago (+0/-0)
[ + ] cyclops1771
[ - ] cyclops1771 0 points 4 yearsApr 2, 2021 16:04:38 ago (+0/-0)
[ + ] MrPim
[ - ] MrPim 0 points 4 yearsApr 2, 2021 16:25:28 ago (+0/-0)
English is complicated at best.
[ + ] cyclops1771
[ - ] cyclops1771 0 points 4 yearsApr 2, 2021 20:10:10 ago (+0/-0)
Yes, yes it is.