transition

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Change from one form, state, style, or place to another.
• noun Change from one subject to another in discourse.
• noun A word, phrase, sentence, or series of sentences connecting one part of a discourse to another.
• noun Change from one key or tonality to another.
• noun A passage connecting two themes or sections, usually changing to a new key or tonality.
• noun Genetics A point mutation in which a pyrimidine is replaced by another pyrimidine, or a purine is replaced by another purine.
• noun Sports The process of changing from defense to offense or offense to defense without a stoppage in play, as in basketball or hockey.
• noun A period during childbirth that precedes the expulsive phase of labor, characterized by strong uterine contractions and nearly complete cervical dilation.
• intransitive verb To make a transition.
• intransitive verb Sports To change from defense to offense or offense to defense without a stoppage in play.

from The Century Dictionary.

• noun Passage from one place, state, or act to another; change: as, a sudden transition from anger to mirth; a state of transition.
• noun In rhetoric, a passing from one subject to another.
• noun In music, same (usually) as modulation.
• noun In geology, the English form of the name (used attributively or as an adjective) given by Werner to certain strata which he investigated in northern Germany, and found to have, to a certain extent, the mineral character of the socalled primitive rocks, while also exhibiting indications of a mechanical origin, and even containing occasional fossils, thus indicating a transition or passage from primary to secondary.
• noun In art hist., an epoch or stage of change from one style or state of development in art to the next succeeding; especially, in Greek art, the stage of change from the archaic to the bloom of art, and in medieval art, that from the round-arched or Romanesque to the Pointed style.

from the GNU version of the Collaborative International Dictionary of English.

• noun Passage from one place or state to another; charge.
• noun (Mus.) A direct or indirect passing from one key to another; a modulation.
• noun (Rhet.) A passing from one subject to another.
• noun (Biol.) Change from one form to another.
• noun (Geol.) a term formerly applied to the lowest uncrystalline stratified rocks (graywacke) supposed to contain no fossils, and so called because thought to have been formed when the earth was passing from an uninhabitable to a habitable state.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The process of change from one form, state, style or place to another.
• noun A word or phrase connecting one part of a discourse to another.
• noun music A brief modulation; a passage connecting two themes.
• noun genetics A point mutation in which one base is replaced by another of the same class (purine or pyrimidine); compare transversion.
• noun A change from defense to attack, or attack to defense.
• noun medicine The onset of the final stage of childbirth.
• noun education Professional special education assistance for children or adults in the process of leaving one educational environment or support program for another to relatively more independent living.
• noun skating A change between forward and backward motion without stopping.
• noun LGBT The process or act of changing from one gender role to another, or of bringing one's outward appearance in line with one's internal gender identity.
• verb intransitive To make a transition.
• verb LGBT To change from one gender role to another, or bring one's outward appearance in line with one's internal gender identity.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a passage that connects a topic to one that follows
• noun the act of passing from one state or place to the next
• verb cause to convert or undergo a transition
• verb make or undergo a transition (from one state or system to another)
• noun an event that results in a transformation
• noun a change from one place or state or subject or stage to another
• noun a musical passage moving from one key to another