The Free On-line Dictionary of Computing (30 December 2018):

linear type

   1.  An attribute of values which are used
   exactly once: they are neither duplicated nor destroyed.  Such
   values require no garbage collection, and can safely be
   updated in place, even if they form part of a data structure.

   Linear types are related to the linear logic of J.-Y Girard.
   They extend Schmidt's notion of single threading, provide an
   alternative to Hudak and Bloss' update analysis, and offer a
   practical complement to Lafont and Holmström's elegant linear
   languages.

   ['Use-Once' Variables and Linear Objects - Storage Management,
   Reflection and Multi-Threading, Henry Baker.
   (http://home.pipeline.com/~hbaker1/Use1Var.html)].

   ["Linear types can change the world!", Philip Wadler,
   "Programming Concepts and Methods", April 1990, eds. M. Broy,
   C. Jones, pub. North-Holland, IFIP TC2 Working Conference on
   Programming Concepts and Methods, Sea of Galilee, Israel].

   (1995-03-03)