D defs.my
Entry 1 sense Webster, 1913

Concentrative

· Con·cen·tra·tive · IPA /kənˈsɛntɹətɪv/
01 a. Serving or tending to concentrate; characterized by concentration.
  1. 1.
    Serving or tending to concentrate; characterized by concentration.
    “A discrimination is only possible by a concentrative act, or act of attention.” Sir W. Hamilton.