1) Copulate 2) Couple 3) Mate 4) Pair 
a cross between a hybrid and one of it's parent plants
To cross (mate) with one parent. 
the mating of a hybrid organism (offspring of genetically unlike parents) with one of its parents or with an organism genetically similar to the ... [3 related articles]
The mating of a two-breed crossbred individual back to one of its parental breeds. Example: A Hereford-Angus crossbred cow bred back to an Angus bull.
The mating of a two-breed crossbred offspring back to one of its parental breeds. Example: A Hereford-Angus cross cow bred back to an Angus bull. 
Crossing an organism with one of its parent organisms.
(bak´kros) in experimental genetics, a cross between an offspring and one of its parents, or an organism genetically identical to one of its parents.
Offspring resulting from the mating of a hybrid bird with one of its parental species.
A cross between an animal that is heterozygous for alleles obtained from two parental strains and a
Crossing a hybrid back to one of the original parents, called the recurrent parent. In agronomy, the recurrent parent is usually a single genotype, often a named variety. In forestry, the recurrent parent is usually a different genotype from the same species or population. (This is done to prevent inbreeding depression.) Example: collecting pollen ...
Type: Term Pronunciation: bak′kros Definitions: 1. The mating between an animal that is homozygous at a locus of interest and an animal that is heterozygous, commonly from the same ancestral stock. Synonyms: testcross
a cross between a hybrid and one of it's parent plants
When a hybrid mates with one of their parent species.
[v] - mate a hybrid of the first generation with one of its parents
verb mate a hybrid of the first generation with one of its parents
Offspring resulting from the mating of a hybrid bird with one of its parental species.