The Collaborative International Dictionary of English v.0.48:

Paromology \Par`o*mol"o*gy\, n. [Gr. fr. ?, fr. ? to grant; ?
   by, near + ? to speak together, agree. See Homologous.]
   (Rhet.)
   A concession to an adversary in order to strengthen one's own
   argument.
   [1913 Webster]