1) Alike 2) Fungible 3) Reciprocal 4) Replaceable 5) Same 6) Symmetric 7) Symmetrical 
• (a.) Admitting of exchange or mutual substitution. • (a.) Following each other in alternate succession; as, the four interchangeable seasons.
capable of replacement by a similar item without impairing the specified performancea component is interchangeable when it meets the original performance specifications and is intermountable. In the case of connectors, interchangeability applies only to connector mated sets, since individual connectors are not necessarily intermateable
In`ter·change'a·ble adjective [ Confer Old French entrechangeable .] 1. Admitting of exchange or mutual substitution. ' Interchangeable warrants.' Bacon. 2. Following each other in alternate succession; as, the four interchangeable seasons. Holder....
[adj] - (mathematics, logic) such that the arguments or roles can be interchanged
adjective (mathematics, logic) such that the arguments or roles can be interchanged; `the arguments of the symmetric relation, `is a sister of,` are interchangeable`
(of two things) capable of being put or used in the place of each other: interchangeable symbols. · (of one thing) capable of replacing or changing places with something else: an interchangeable part.