The Collaborative International Dictionary of English v.0.48:

Paracentesis \Par`a*cen*te"sis\
   (p[a^]r`[.a]*s[e^]n*t[=e]"s[i^]s), n. [L., fr. Gr.
   parake`nthsis, fr. parakentei^n to pierce at the side, to
   tap.] (Med.)
   The perforation of a cavity of the body with a trocar,
   aspirator, or other suitable instrument, for the evacuation
   of effused fluid, pus, or gas; tapping.
   [1913 Webster] paracentric

WordNet (r) 3.0 (2006):

paracentesis
    n 1: centesis of the belly to remove fluid for diagnosis [syn:
         abdominocentesis, paracentesis]