complex
Pronunciation: /ˈkɒmplɛks/
adjective
- 1consisting of many different and connected parts: a complex network of water channels
- not easy to analyse or understand; complicated or intricate: a complex personality the situation is more complex than it appears
noun
- 1a group or system of different things that are linked in a close or complicated way; a network: a complex of mountain roads
- a group of similar buildings or facilities on the same site: a leisure complex a complex of hotels
- 2 Psychoanalysis a related group of repressed or partly repressed emotionally significant ideas which cause psychic conflict leading to abnormal mental states or behaviour.
- informal a strong or disproportionate concern or anxiety about something: there’s no point having a complex about losing your hair
- 3 Chemistry an ion or molecule in which one or more groups are linked to a metal atom by coordinate bonds: two guanine bases can attach themselves to the same platinum atom, forming a stable complex
- any loosely bonded species formed by the association of two molecules: cross-linked protein-DNA complexes
verb

Origin:
mid 17th century (in the sense 'group of related elements'): from Latin complexus, past participle (used as a noun) of complectere 'embrace, comprise', later associated with complexus 'plaited'; the adjective is partly via French complexe