The Collaborative International Dictionary of English v.0.48:

Pennant \Pen"nant\ (p[e^]n"nant), n. [OE. penon, penoun, pynoun,
   OF. penon, F. pennon, fr. L. penna feather. See Pen a
   feather, and cf. Pennon, Pinion.] (Naut.)
   (a) A small flag; a pennon. The narrow pennant, or long
       pennant (called also whip or coach whip) is a long,
       narrow piece of bunting, carried at the masthead of a
       government vessel in commission. The board pennant is
       an oblong, nearly square flag, carried at the masthead of
       a commodore's vessel. "With flags and pennants trimmed."
       --Drayton.
   (b) A rope or strap to which a purchase is hooked.
       [1913 Webster] Pennate