Counterpart Coun"ter*part` (koun"t?r-p?rt`), n. 1. A part corresponding to another part; anything which answers, or corresponds, to another; a copy; a duplicate; a facsimile. In same things the laws of Normandy agreed with the laws of England, so that they seem to be, as it were, copies or counterparts one of another. --Sir M. Hale. 2. (Law) One of two corresponding copies of an instrument; a duplicate. 3. A person who closely resembles another. 4. A thing may be applied to another thing so as to fit perfectly, as a seal to its impression; hence, a thing which is adapted to another thing, or which supplements it; that which serves to complete or complement anything; hence, a person or thing having qualities lacking in another; an opposite. O counterpart Of our soft sex, well are you made our lords. --Dryden.