difficult to penetrate; incomprehensible to one of ordinary understanding or knowledge; "the professor's lectures were so abstruse that students tended to avoid them"; "a deep metaphysical theory"; "some recondite problem in historiography"
termination of operations; "they regretted the closure of the day care center"
a Gestalt principle of organization holding that there is an innate tendency to perceive incomplete objects as complete and to close or fill gaps and to perceive asymmetric stimuli as symmetric
a rule for limiting or ending debate in a deliberative body
terminate debate by calling for a vote; "debate was closured"; "cloture the discussion"