Definitions
from Wiktionary, Creative Commons Attribution/ShareAlike License
 n. A hypothetical object extending across a number of (often specified) spatial dimensions, with strings in string theory seen as onedimensional examples.
Etymologies
Examples

This treatment, of course, assumes the recovery of the Kerr metric in braneworlds which we have found to the first order in the ratio of the brane separation to the radius of the AdS$_5$, $ (ell/r) $.

The brane is a distinguished submanifold (the skin) in the higherdimensional space.

So what has transpired is that there is now the 0brane, which is a field at a point.

This submanifold is called the brane (as in membrane).

More ambiguous is the view from the other side of the "brane" which verifies the father's lifelong quest, but simultaneously seems detached from the central theme.
REVIEW: The Solaris Book of New Science Fiction, Volume 3 edited by George Mann

One example, he said, is to confine all the forces of our universe to a fourdimensional plane known as a membrane, or "brane," which is sandwiched between other branes.

Our spacetime cosmology is associated with a D3brane which is evolving in the so called Mtheory bulk.
If We Live in a Multiverse, How Many Are There?  Universe Today

Even to speak of the future was to create another "brane," another branch of the great multiversal tree.

Proposed in 2002 by Paul Steinhardt of Princeton University and Neil Turok from the University of Cambridge, the model argues that our universe exists on a 3D region called a "brane" separated from similar branes by a fourth spatial dimension.

and by definition i better shut up the only big bang i know about is what rush got with all that viagra in his suitcase and don't ask me what a 'brane' is
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fbharjo commented on the word brane
in the samebranevein?
February 13, 2014
skipvia commented on the word brane
From Wikipedia:
In theoretical physics, a membrane, brane, or pbrane is a spatially extended, mathematical concept that appears in string theory and its relatives (Mtheory and brane cosmology). The variable p refers to the spatial dimension of the brane. That is, a 0brane is a zerodimensional pointlike particle, a 1brane is a string, a 2brane is a "membrane", etc. Every pbrane sweeps out a (p+1)dimensional world volume as it propagates through spacetime.
February 21, 2008