'self-tolerance' is a compound of 'self' and 'tolerance'. 'Self' originates from Old English 'self' (related to Proto-Germanic '*selbaz'), meaning 'the same' or 'one's own', and 'tolerance' originates from Latin 'tolerantia' (from 'tolerare') meaning 'to bear' or 'to endure'.

'tolerance' came into English via Old French 'tolérance' and Middle English 'tolerence', evolving into the modern English word 'tolerance'; 'self' has remained in English from Old English to modern use, and the compound 'self-tolerance' formed by combining these elements describes bearing or accepting of the self.

Initially, components conveyed 'one's own' ('self') and 'the ability to bear or endure' ('tolerance'); over time the compound has come to mean both psychological acceptance of oneself and, in scientific contexts, the immune system's nonreactivity to the body's own tissues.