Sure is an adjective ( or a participle? ) in the plural, so it should not be defined here, but refer to its singular masculine. The problem is . . . which one? . It is clearly a popular deformation for another word, which is surely used locally. It can come from escarmenado, hair, wool that detangles, that takes away the carmenado, which is a regression of carding and would also create versions like this 'encarmenado' to "curl, beat the hair"; but it doesn't officially exist in Spanish, nor do I really know if it's used colloquially somewhere. Taking into account deformations, trolling and possible OCR errors, you can also see chastened, caramelized, weeded, perched, sloping, heading, incarnate, . . .