juncture

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act of joining or the condition of being joined.
2. n. A place where two things are joined; a junction or joint.
3. n. A point in time, especially a critical point. See Synonyms at crisis.
4. n. The transition or mode of transition from one sound to another in speech.

Century Dictionary and Cyclopedia

1. n. A joining; junction.
2. n. The line or point at which two bodies are joined; a joint or articulation; a seam.
3. n. A point of time; particularly, a time rendered critical or important by a concurrence of circumstances; a conjuncture.
4. n. In geometry, either the instantaneous union of a collection of objects which are just moving in coincidence of place, thereafter to be for some lapse of time one object, or the instantaneous loss of one or more dimensions by the gradual shrinkage of a body, this smaller dimensionality lasting through a period of time.

Wiktionary

1. n. a place where things join, a junction
2. n. a critical moment in time

GNU Webster's 1913

1. n. obsolete A joining; a union; an alliance.
2. n. The line or point at which two bodies are joined; a joint; an articulation; a seam.
3. n. A point of time; esp., one made critical or important by a concurrence of circumstances; hence, a crisis; an exigency.

WordNet 3.0

1. n. a crisis situation or point in time when a critical decision must be made
2. n. the shape or manner in which things come together and a connection is made
3. n. an event that occurs at a critical time