Morgellons UK /mɔː(ɹ)ˈd͡ʒɛlənz/US /mɔɹˈd͡ʒɛlənz/ noun2 •An unproven skin disorder, usually thought to be delusional parasitosis, characterized by skin lesions in which fibers are found. •(no longer used) A disease causing hairs to grow on the backs of children.