underlying: Meaning and Definition of

un•der•ly•ing

1. lying or situated beneath, as a substratum.
2. fundamental; basic: the underlying cause of their discontent.
3. implicit; discoverable only by close scrutiny or analysis: an underlying seriousness in his witticisms.
4. (of a claim, mortgage, etc.) taking precedence; anterior; prior.
5. belonging to an earlier stage in the transformational derivation of a sentence or other structure; belonging to the deep structure.