Definition of multichain:
(adj) :
(chemistry) Of or pertaining to more than one chain.
(adj) :
(probability theory) Of a Markov chain, consisting of two or more closed sets of recurrent states plus (optionally) a set of states that do not belong to any of the closed sets.
(n) :
(probability theory) A multichain Markov chain.
(n) :
An ordered subset of a poset; a generalization of a chain that allows inequalities that are not strict.