interchangeable β (of two things) capable of being put or used in the place of each other: interchangeable symbols.
of a kind β a class or group of individual objects, people, animals, etc., of the same nature or character, or classified together because they have traits in common; category: Our dog is the same kind as theirs.
synonymous β having the character of synonyms or a synonym; equivalent in meaning; expressing or implying the same idea.
noun equivalent
counterpart β Someone's or something's counterpart is another person or thing that has a similar function or position in a different place.
opposite number β counterpart; equivalent: New members with an interest in folk art will find their opposite numbers in the association's directory.
twin β either of two children or animals brought forth at a birth.
peer β a person of the same legal status: a jury of one's peers.
match β a person or thing that equals or resembles another in some respect.
obverse β the side of a coin, medal, flag, etc., that bears the principal design (opposed to reverse).
opposite β situated, placed, or lying face to face with something else or each other, or in corresponding positions with relation to an intervening line, space, or thing: opposite ends of a room.
carbon copy β If you say that one person or thing is a carbon copy of another, you mean that they look or behave exactly like them.
dead ringer β a person or thing that closely resembles another; ringer: That old car is a dead ringer for the one we used to own.