sermountain UK /ˈsɜːˌmaʊn.tɪn/US /ˈsɝˌmaʊn.tən/ noun1 •(no longer used) A plant of the genus Laserpitium.La Cerda fancies it to be the Siler montanum, or Sermountain, because he thinks it more elegant for the poet to speak of two which grow in the plains, and two in the rivers[…] — 1814