The Collaborative International Dictionary of English v.0.48:

Parcener \Par"ce*ner\, n. [Of. par[,c]onnier, parsonnier, fr.
   parzon, par[,c]un, parcion, part, portion, fr. L. partitio a
   division. See Partition, and cf. Partner.] (Law)
   A coheir, or one of two or more persons to whom an estate of
   inheritance descends jointly, and by whom it is held as one
   estate.
   [1913 Webster]