The terms "kink" and "antikink" have been used by both physicists and applied mathematicians for many years to describe solutions to nonlinear partial differential equations. They have precise mathematical meaning and are known as topological solitons. The "kink-antikink bound state" represents a different class of solutions, which describe the emergence of coherent structures that contain internal dynamical motion (hence the term, "breather soliton"). Kink-antikink bound states are encountered in a large number of diverse areas in nonlinear science, and are of particular interest to physicists and mathematicians working in these areas.
For the molecular biologist, the word "kink" means a sharp bend in DNA due to a highly localized conformational change in sugar residues or phosphodiester linkages. Although this terminology is somewhat restricted, it has proven useful in the DNA area and poses no problem provided physicists and biologists agree on the meaning of the word "kink" in these two different contexts.