- concealed but detectable: underlying guilt
- fundamental; basic
- lying under
- (of a claim, liability, etc) taking precedence; prior
WordReference Random House Learner's Dictionary of American English © 2019
- lying beneath something else:an underlying layer of rock.
basic:an underlying cause.
- that can be discovered only by close analysis or examination:Loyalty is the underlying theme of the story.
- lying or situated beneath, as a substratum.
basic:the underlying cause of their discontent.
discoverable only by close scrutiny or analysis:an underlying seriousness in his witticisms.
- Business(of a claim, mortgage, etc.) taking precedence;
- Linguisticsbelonging to an earlier stage in the transformational derivation of a sentence or other structure;
belonging to the deep structure.
- underlie + -ing2 1605–15
- to lie under.
- to form the foundation of.
- to lie under or beneath;
be situated under.
- to be at the basis of;
form the foundation of.
- Grammarto function as the root morpheme or original or basic form of (a derived form):The form "boy'' underlies "boyish.''
- Business[Finance.]to be primary to another right or security.
- Middle English underlyen (verb, verbal), Old English underlicgan. See under-, lie2 bef. 900
- to lie or be placed under or beneath
- to be the foundation, cause, or basis of: careful planning underlies all our decisions
- to take priority over (another claim, liability, mortgage, etc)
- to be the root or stem from which (a word) is derived: "happy" underlies "happiest"