【Break】 , 【gap】 , 【interruption】 , 【interval】 , 【interim】 ,  【hiatus】 , 【lacuna】 all denote a lapse in continuity.

【Break】  applies not only to a lapse in continuity in something material or substantial, but also in things (as a course of action or something having extension in time) that may be considered in reference to their continuity.

【Gap】 basically applies to an opening (as in a wall or fence) made either by natural decay or by deliberate effort as a means of ingress or egress; the term may also include an opening (as a gorge between mountains) that serves as a passage inward or outward.

【Interruption】 implies a 【break】 that not only makes for a lapse in continuity but that disturbs the procedure (as of an action, a work, or a discourse) and causes a temporary stop or that, less often, makes a void or 【gap】 in space or order.

【Interval】 refers to the distance (as in time or in space) that exists between two things that are basically alike; the term often serves simply as a basis for measuring or suggesting this distance.

【Interim】 applies to the 【interval】 between two events (as the death or abdication of a sovereign and the accession of his successor or the discarding of one method and the instituting of another).

【Hiatus】 applies mainly to an 【interruption】 or lapse in time or continuity, and so implies that something important or essential is missing.

【Lacuna】 may stress the vacuity of a 【gap】 or void and is often used specifically of a blank in a text (as of a manuscript or inscription) where a few words have been omitted or effaced.

In anatomical use the term more often stresses the minuteness than the vacuity of a 【gap】 (as a pit or chamber).