pam·phlet / ˈpamflit/ • n. a small booklet or leaflet containing information or arguments about a single subject.• v. (-phlet·ed, -phlet·ing) [tr.] distribute pamphlets to.

pamphlet small treatise of smaller compass than a ‘book’ XIV; short treatise or booklet on a matter of current or temporary interest XVI. ME. pamflet, paunflet, in AL. panfletus; generalized use of Pamphilet, Panflet (in OF. and MDu. respectively), vernacular name of the L. amatory poem ‘Pamphilus seu de Amore’.
Hence pamphleteer (-EER1) XVII (†pamphleter XVI).