parameter
pa.ram.e.ter \p*-'ram-*t-*r\ \.par-*-'me-trik\ n [NL, fr. para- + Gk metron measure - more at MEASURE] 1: an arbitrary constant each of whose values characterizes a member of a s ystem (as a family of curves); specif : a quantity that describes a statistical population 2: a characteristic element or constant factor - para.met.ric aj