The Collaborative International Dictionary of English v.0.48:

Estafet \Es`ta*fet"\, Estafette \Es`ta*fette"\, n. [F.
   estafette, cf. Sp. estafeta; fr. It. stafetta, fr. staffa
   stirrup, fr. OHG. stapho footstep, footprint, G. stapfe; akin
   to E. step.]
   A courier who conveys messages to another courier; a military
   courier sent from one part of an army to another.
   [1913 Webster]