complex

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

• 2 Mathematics denoting or involving numbers or quantities containing both a real and an imaginary part.

• 3 Chemistry denoting an ion or molecule in which one or more groups are linked to a metal atom by coordinate bonds: in naming complex ions, the names of the ligands are cited first

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

• make (an atom or compound) form a complex with another:the DNA was complexed with the nuclear extract