WordWeb Online

1. (mathematics, logic) such that the arguments or roles can be interchanged
   "the arguments of the symmetric relation, 'is a sister of,' are interchangeable"
    
2. Capable of replacing or changing places with something else; permitting mutual substitution without loss of function or suitability
   "interchangeable electric outlets" "interchangeable parts"; "exchangeable electric outlets" "interchangeable parts"; "similar electric outlets" "interchangeable parts"; "standardized electric outlets" "interchangeable parts"; "standardised electric outlets" "interchangeable parts"
   - exchangeable, similar, standardized, standardised [Brit]

See also: interchangeableness, interchangeably, replaceable, symmetric, symmetrical

Encyclopedia: Interchangeable