Definition of underlie in US English:



[with object]
  • 1(especially of a layer of rock or soil) lie or be situated under (something).

    • ‘The plants were growing from several fissures in the mafic bedrock that underlies the creek.’
    • ‘Bangkok is located on a floodplain composed of deltaic deposits, including the well-known soft Bangkok clay, underlain by alternating layers of clays and sands that extend to depths of more than 1,000 m.’
    • ‘The Yucatán peninsula is underlain by limestone and evidently rose from the sea in ancient times.’
    • ‘If the cracks extend deep enough, the seawater can come into contact with mantle rocks that underlie the crust.’
    • ‘Poor drainage areas are most notable in the lands underlain by older metamorphic rocks of the Klamath Mountains to the south.’
    • ‘Canadian vineyards are planted on a wide variety of soil types underlain by diverse bedrock geology.’
    • ‘The Adirondack Mountains, in the northern part of the study area, are an exception in that they are largely underlain by crystalline rock.’
    • ‘The soil that underlies much of Dublin was deposited during the last ice age, about 10,000 years ago.’
    • ‘It lies within the discordantly aligned Balygychan-Sugoi basin, which is underlain by volcanic rocks and carbonaceous molasses that cover the Verkhoyansk terrigenous rocks.’
    • ‘For example, many shorefaces - the dynamic zones between the continental shelf and the beach - are not simply surfaces of sand but rather are underlain by rock or mud.’
    • ‘Furthermore, in cultivated soils, dense compact subsoils frequently underlie the loosened topsoil.’
    • ‘Large expanses of boreal forest and tundra are underlain by permafrost, a layer of permanently frozen soil found underneath the active, seasonally thawed soil.’
    • ‘Much of this zone is underlain by permafrost and is the most southern Subarctic barrens in the world.’
    • ‘Colchester in Essex, where London clay underlies the estuaries, was the home of the renowned Pyfleet oysters.’
    • ‘The ground is underlain by permafrost, a layer of soil that remains frozen throughout the year and that may extend deep into the earth (in Siberia, it has been reported at a depth of 4,757 feet).’
    • ‘The interior of the basin is underlain by the Quaternary floodplain deposits and terraces associated with the Mae Ping River.’
    • ‘Steep slopes underlain by stony soils form appealing vineyard sites, but they can be susceptible to rapid soil erosion during storms.’
    • ‘Most of the mowed fields in the central part of the park are underlain with soil.’
    • ‘The rock underlying the ruins was limestone and, as a result, the soil was thin and dry.’
    dormant, quiescent, inactive, untapped, unused
    View synonyms
    1. 1.1 Be the cause or basis of (something)
      ‘the fundamental issue that underlies the conflict’
      ‘the underlying causes of poverty and drug addiction’
      • ‘Controversial social and political issues underlay these emotional exchanges.’
      • ‘If justiciability is the real issue underlying these terms then this should be faced directly.’
      • ‘I think that is a reasonably accurate statement of the real issue and it underlies this particular case.’
      • ‘Perhaps that is the conflict that underlies his and my shared anger.’
      • ‘It also details the various technical aspects of the project and highlights the principal distributional conflict that underlay the reform process.’
      • ‘This issue increasingly underlies our economic and environmental problems.’
      • ‘However, the central thought which underlies them is simple, though it can be expressed in a number of different ways.’
      • ‘While he focuses on the kiwi dollar, he shows how the underlying issues are global.’
      • ‘The authors' analysis does a great deal to clarify the ethical issues that underlie these intuitive distinctions.’
      • ‘Political motivations most likely underlie this transformation of tradition.’
      • ‘But I suspect that what underlies these concerns is a deeper fear about the loss of a sort of stability in the region which they helped craft and maintain.’
      • ‘Well let me take the larger issue that I think underlies the question.’
      • ‘Instead, I would like to focus on a few recurring issues that seem to underlie discussions.’
      • ‘The discussions are open and frank, and the importance of obeying the game laws underlies all possible strategies.’
      • ‘We will hold informal meetings to try and tease out the underlying issues.’
      • ‘Before examining the case law it may be helpful to understand the central issues which underlie this area.’
      • ‘When we get to the appeal, let us focus on the issues that underlie the appeal.’
      • ‘One should not focus on the media attention at the expense of the underlying issue.’
      • ‘This is the underlying issue which campaigners agree must be tackled in years to come.’
      • ‘I think what underlies this is a fundamental problem with the movie.’
      fundamental, basic, basal, primary, prime, first, cardinal, central, principal, chief, key, elementary, elemental, rudimentary, root, intrinsic, essential
      View synonyms


Old English underlicgan ‘be subject or subordinate to’ (see under-, lie).