solid

Concise Oxford English Dictionary © 2008 Oxford University Press:
solid/ˈsɒlɪd/

▶adjective (solider, solidest)

• 1 firm and stable in shape; not liquid or fluid: solid fuel.

  ■ strongly built or made.

• 2 Geometry three-dimensional.

  ■ relating to three-dimensional objects.

• 3 not hollow or having spaces or gaps.

  ■ consisting of the same substance throughout.

  ■ (of time) continuous.

• 4 dependable; reliable.

  ■ sound but without special qualities.

• 5 (solid with) US informal on good terms with.

• 6 Austral. informal severe; unfair.

▶noun

• 1 a solid substance or object.

  ■ (solids) food that is not liquid.

• 2 Geometry a three-dimensional body or geometric figure.

– derivatives
solidity noun,
solidly adverb,
solidness noun.

– origin ME: from L. solidus; rel. to salvus ‘safe’ and sollus ‘entire’.