n. The act or result of joining; a joint or juncture.
The Century Dictionary and Cyclopedia
n. A line of junction; a. joint.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. the act of bringing two things into contact (especially for communication)
Word Usage
"By the end of the episode the 2 doctors do rejoin as 1 single timelord again, this joining is the reference of the 3 fold man (single heart doctor + single heart doctor = 2 heart doctor)."