Seclusion, Isolation, Avoidance

The base that specifically denotes isolation is insl*. Another base, mon*, means "alone, single," but does not explicitly connote isolation. The causative derivatives of mon* (monif*, moniv*) can indicate becoming isolated, but only in the sense of becoming single.

Seclusion, privacy, retirement, eremitism, anchoretism, anchoritism, reclusion, recess; suspension; snugness &c. adj.; concealment, delitescence; rustication, rus in urbe [L.], ruralism, rurality [rare], solitude; solitariness (singleness) [See Unity]; isolation; “splendid isolation”; loneliness &c. adj.; estrangement from the world, voluntary exile; aloofness.
depopulation, desertion, desolation; wilderness (unproductive) [See Unproductiveness]; howling wilderness; rotten borough, Old Sarum [Eng.].
UNSOCIABILITY, unsociableness, dissociability, dissociality; inhospitality, inhospitableness &c. adj.; domesticity, self-sufficiency, Darby and Joan.