1isolate or hide away:she is sequestered in deepest Dorsetthe artist sequestered himself in his studio for two years
2another term for sequestrate.their property was sequestered by Parliament
3 Chemistry form a chelate or other stable compound with (an ion, atom, or molecule) so that it is no longer available for reactions:non-precipitating water softeners use complex phosphates to sequester calcium and magnesium ions (as adjective sequestering)the organic sequestering agent EDTA