Webster's Revised Unabridged Dictionary · 1913

Complex

Complex (kom"pleks) , adjective

[Latin complexus, past participle of complecti to entwine around, comprise; com- + plectere to twist, akin to plicare to fold. See Plait, n.]

1.
Composed of two or more parts; composite; not simple; as, a complex being; a complex idea.
Ideas thus made up of several simple ones put together, I call complex; such as beauty, gratitude, a man, an army, the universe. — Locke
2.
Involving many parts; complicated; intricate.
When the actual motions of the heavens are calculated in the best possible way, the process is difficult and complex. — Whewell
Collocations (2)
Complex fraction , See Fraction.
Complex number (Mathematics) , in the theory of numbers, an expression of the form a + br-1, when a and b are ordinary integers.

Complex , noun

[Latin complexus]

Assemblage of related things; collection; complication.
This parable of the wedding supper comprehends in it the whole complex of all the blessings and privileges exhibited by the gospel. — South
Collocations (1)
Complex of lines (Geometry) , all the possible straight lines in space being considered, the entire system of lines which satisfy a single relation constitute a complex; as, all the lines which meet a given curve make up a complex. The lines which satisfy two relations constitute a congruency of lines; as, the entire system of lines, each one of which meets two given surfaces, is a congruency.