1876, Devonshire Association for the Advancement of Science, Literature, and Art, What is the derivation of pilm = dust, so frequently heard in Devon, and its derivatives pilmy, dusty : it pilmeth. ...Pillom is the full word, of which pilm is a contraction. It appears to have been derived from the British word pylor, dust.
1885, Devonshire Association for the Advancement of Science, Literature, and Art, I may quote the famous definition once given in court to enlighten the Bench and the Bar as to the nature of pilm : " Mucks a-drowed and zo vleeth," that is, " mud dried, and so it flies about "—not a bad definition of pilm, which everybody here knows means dust.
Verb
(dialect, impersonal) (meaning uncertain) To have dust blow about