Transition

noun
1.
movement, passage, or change from one position, state, stage, subject, concept, etc., to another; change:
the transition from adolescence to adulthood.
2.
Music.

a passing from one key to another; modulation.
a brief modulation; a modulation used in passing.
a sudden, unprepared modulation.

3.
a passage from one scene to another by sound effects, music, etc., as in a television program, theatrical production, or the like.
verb (used without object)
4.
to make a transition:
He had difficulty transitioning from enlisted man to officer.
5.
to change from one gender identity to another or to align one’s dress, behavior, etc., with one’s gender identity:
My friend is transitioning without hormone therapy or surgery.
noun
1.
change or passage from one state or stage to another
2.
the period of time during which something changes from one state or stage to another
3.
(music)

a movement from one key to another; modulation
a linking passage between two divisions in a composition; bridge

4.
Also called transitional. a style of architecture that was used in western Europe in the late 11th and early 12th century, characterized by late Romanesque forms combined with early Gothic details
5.
(physics)

any change that results in a change of physical properties of a substance or system, such as a change of phase or molecular structure
a change in the configuration of an atomic nucleus, involving either a change in energy level resulting from the emission of a gamma-ray photon or a transformation to another element or isotope

6.
a sentence, passage, etc, that connects a topic to one that follows or that links sections of a written work