reconvention

from The Collaborative International Dictionary of English v.0.48

Reconvention \Re`con*ven"tion\ (-v?n"sh?n), n. (Civil Law)
   A cross demand; an action brought by the defendant against
   the plaintiff before the same judge. --Burrill. Bouvier.
   [1913 Webster]

from Bouvier's Law Dictionary, Revised 6th Ed (1856)

RECONVENTION, civ. law. An action brought by a party who is defendant 
against the plaintiff before the same judge. Reconventio est petitio qua 
reus vicissim, quid ab actore petit, ex eadem, vel diversa causa. Voet, in 
tit. de Judiciis, n. 78; 4 N. S. 439. To entitle the defendant to institute 
a demand in reconvention, it is requisite that such demand, though different 
from the main action, be nevertheless necessarily connected with it and 
incidental to the same. Code of Pr. Lo. art. 375; 11 Lo. R. 309; 7 N. S. 
282; 8 N. S. 516.    
     2. The reconvention of the civil law was a species of cross-bill. 
Story, Eq. Pl. Sec. 402. See Conventio; Bill in chancery. Vide Demand in 
reconvention.