1 : marked by close acquaintance, association, or familiarity; "intimate friend"; "intimate relations between economics, politics, and legal principles" - V.L. Parrington
2 : having mutual interests or affections; of established friendship; "on familiar terms"; "pretending she is on an intimate footing with those she slanders"
3 : innermost or essential; "the inner logic of Cubism"; "the internal contradictions of the theory"; "the intimate structure of matter"