Source : Webster's Revised Unabridged Dictionary (1913)

Cohesive \Co*he"sive\, a.
   1. Holding the particles of a homogeneous body together; as,
      cohesive attraction; producing cohesion; as, a cohesive
      force.

   2. Cohering, or sticking together, as in a mass; capable of
      cohering; tending to cohere; as, cohesive clay.

   {Cohesive attraction}. See under {Attraction}. --
      {Co*he"sive*ly}, adv. -- {Co*he"sive*ness}, n.

Source : WordNet®

cohesive
     adj 1: causing cohesion; "a cohesive agent"
     2: cohering or tending to cohere; well integrated; "a cohesive
        organization"