まんねん Meanings Expression it is assuredly that ... See also: なんです. Words containing まんねん まんねんろう rosemary こもちまんねんぐさ Sedum bulbiferum (species of stonecrop) おのまんねんぐさ needle stonecrop (Sedum lineare) And 3 more. Word lists Osaka dialect Jinuma: Japanese Dictionary · Word lists