of or pertaining to structure; pertaining or essential to a structure.

Biology . pertaining to organic structure; morphological.

Geology . of or pertaining to geological structure, as of rock or strata.

Chemistry . pertaining to or showing the arrangement or mode of attachment of the atoms that constitute a molecule of a substance. Compare structural formula .

resulting from or pertaining to political or economic structure.

of, pertaining to, or based on the assumption that the elements of a field of study are naturally arranged in a systematic structure

structural grammar.

Building Trades .

a part of a structure that carries a load.

the structural member used for such a part.