Definition of moiety in US English:


nounPlural moieties

technical, formal
  • 1Each of two parts into which a thing is or can be divided.

    • ‘The plots show that residues lining the gorge have the largest velocity covariance with the gorge, and residues in the same moiety as the gorge move concertedly away from the gorge when it opens.’
    • ‘Because electronic polarization is accounted for by the choice of background dielectric, dipolar moieties are assigned charges consistent with their permanent dipole moments.’
    • ‘Bond lengths and bond angles are held fixed at standard equilibrium values and aromatic moieties are assigned planar conformations unless found otherwise by experiment.’
    1. 1.1Anthropology Each of two social or ritual groups into which a people is divided, especially among Australian Aborigines and some North American Indians.
      • ‘The basic auafangai practice consisted of attaching specific animal or plant names and designs to particular patrilineal descent groups, whether lineages, clans or moieties.’
      • ‘Tlingit society is divided into two primary clans or moieties, subclans or clans, and houses.’
      • ‘Once the initiates, who are of the receiving moiety, have seen the tableau and danced with headdresses all night long, this beautiful structure is rapidly dismantled.’
      • ‘In this way the matrilineal moieties may also be referred to as vara as well as tavalui ‘sides’.’
      • ‘The matrilineal moieties, for example, articulate the matrilineally transmitted ‘flesh’ or totems.’
    2. 1.2 A part or portion, especially a lesser share.
      share, slice, quota, part, bit, percentage, amount, quantity, ration, piece, fraction, division, subdivision, allocation, allotment, measure, apportionment
      View synonyms
    3. 1.3Chemistry A distinct part of a large molecule.
      ‘the enzyme removes the sulfate moiety’
      • ‘In addition, this secondary amine presents some steric impediment by the glucose molecule from the terpenoid moiety.’
      • ‘One is the direct effect of hydrogen bonding by water molecules and the other is the polarizing field of neighboring polar molecular moieties.’
      • ‘A sulfonamide is a chemical entity characterized by a sulfur dioxide and nitrogen moiety directly linked to a benzene ring.’
      • ‘The volume of a hydrocarbon chain, v, does not change in the course of membrane deformations, because the hydrocarbon moiety of a lipid molecule is practically incompressible.’
      • ‘Possible couplings might be fluorinated groups with hydrocarbons, hydrophilic and hydrophobic moieties, siloxanes, and hydrocarbons, etc, and in the present case, chiral and achiral halves.’


Late Middle English: from Old French moite, from Latin medietas ‘middle’, from medius ‘mid, middle’.