The Collaborative International Dictionary of English v.0.48:

Detinue \Det"i*nue\ (?; 277), n. [OF. detinu, detenu, p. p. of
   detenir to detain. See Detain.]
   A person or thing detained; (Law) A form of action for the
   recovery of a personal chattel wrongfully detained.
   [1913 Webster]

   Writ of detinue (Law), one that lies against him who
      wrongfully detains goods or chattels delivered to him, or
      in possession, to recover the thing itself, or its value
      and damages, from the detainer. It is now in a great
      measure superseded by other remedies.
      [1913 Webster]

WordNet (r) 3.0 (2006):

writ of detinue
    n 1: a writ ordering the release of goods that have been
         unlawfully detained

Bouvier's Law Dictionary, Revised 6th Ed (1856):

WRIT OF DETINUE, practice. A writ which lies where a party claims the
specific recovery of goods and chattels, or deeds and writings detained from
him. This is seldom used: trover is the more frequent remedy, in cases where
it may be brought.