Definition of geometrid in US English:



  • A moth of a large family (Geometridae), distinguished by having caterpillars (loopers) that mimic small twigs in appearance and move by looping and straightening the body.

    Also called geometer
    • ‘There aren't very large numbers of macro moths, just a few noctuids, some small pyralids, and a handful of geometrids.’
    • ‘All analysis is based on comparison of melanic and nonmelanic forms, without reference to genotype (the melanic forms in the two geometrids are dominant).’
    • ‘Identification of most caterpillars was problematic so ecological groupings were used to create five subgroups: a bract-associated morphospecies, foliage-associated taxa, geometrids, and a lichen-associated morphospecies.’


Late 19th century: from modern Latin Geometridae (plural), from the genus name Geometra, from Greek geōmetrēs (see geometer).