'underlying' definitions:

Definition of 'underlying'

(from WordNet)
adjective
In the nature of something though not readily apparent; "shortcomings inherent in our approach"; "an underlying meaning" [syn: implicit in(p), inherent, underlying]
adjective
Located beneath or below
adjective
Being or involving basic facts or principles; "the fundamental laws of the universe"; "a fundamental incomatibility between them"; "these rudimentary truths"; "underlying principles" [syn: fundamental, rudimentary, underlying]

Definition of 'underlying'

From: GCIDE
  • underlying \un`der*ly"ing\, a.
  • 1. Lying under or beneath; as, the underlying strata of a locality. [1913 Webster]
  • 2. Hence: Fundamental; basic; as, underlying principles; underlying causes. [1913 Webster +PJC]
  • 3. Implicit; not immediately obvious; requiring careful scrutiny to discover; as, the underlying sarcasm in her seemingly innocuous remark.. [PJC]