Synonyms of self-contained

3 Syllables
reserved, sovereign, self-reliant, autarchic, freewheeling, unaided, self-ruling, unallied
4 Syllables
self-controlled, self-restrained, absolute, non-partisan, separated, autonomous, impassive, non-aligned, independent, nonpartisan, self-sufficient, autarchical, nonaligned, self-governing, self-supporting, unconnected, unconstrained, uncontrolled, separate
5 Syllables
inexcitable, self-determining, unregimented
6 Syllables
uncompanionable, individualistic