Synonyms and related words :
a certain, a deux, an, any, any one, anybody, anyone, anything, atomic, aught, both, correspondingly, exclusive, for two, identically, in kind, in like manner, in that way, individual, indivisible, integral, irreducible, like, like that, like this, likewise, lone, monadic, monistic, one, similarly, simple, single, singular, so, sole, solid, solitary, tete-a-tete, the two, thus, unanalyzable, undivided, uniform, unique, unitary, whole