epexegesis



ep-ex-e-ge'-sis
from Gk. epi, "in addition" and
exegeisthai, "to explain"



When one interprets what one has just said. A kind of
redefinition or self-interpretation (often signaled by
constructions such as "that is to say...").

Examples

I'm afraid we've run up against the bamboo curtain—that is to say, an
economic and political barrier in the East as real as the iron curtain has
been in the West.

http://humanities.byu.edu/rhetoric/Figures/E/epexegesis.htm