Main Entry: un·der·ly·ing

Pronunciation: \ˌən-dər-ˈlī-iŋ\

Function: adjective

Date: 1611

1 a : lying beneath or below <the underlying rock is shale> b : basic, fundamental <an investigation of the underlying issues>
2 : evident only on close inspection : implicit
3 : anterior and prior in claim <underlying mortgage>
4 : of or being present in deep structure <underlying word order>