The Collaborative International Dictionary of English v.0.48:

Hind \Hind\, a. [Compar. Hinder; superl. Hindmost, or
   Hindermost.] [OE. hind, adv., back, AS. hindan behind. See
   Hinder, a.]
   In the rear; -- opposed to front; of or pertaining to the
   part or end which follows or is behind, in opposition to the
   part which leads or is before; as, the hind legs or hind feet
   of a quadruped; the hind man in a procession.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hindermost \Hind"er*most`\, Hindmost \Hind"most`\, a. [The
   superlative of hind. See Hind, a.] [Cf. AS. hindema (akin
   to Goth. hindumists), a superlative from the same source as
   the comparative hinder. See Hinder, a., and cf.
   Aftermost.]
   Furthest in or toward the rear; last. "Rachel and Joseph
   hindermost." --Gen. xxxiii. 2.
   [1913 Webster]

WordNet (r) 3.0 (2006):

hindermost
    adj 1: located farthest to the rear [syn: backmost,
           hindermost, hindmost, rearmost]