Is it ensure, insure, or assure?
in modern prosody, a pause within a poetic line that breaks the regularity of the metrical pattern. It is represented in scansion by the sign . The caesura sometimes is used to emphasize the formal metrical construction of a line, but it more often introduces the cadence of natural speech patterns and habits of phrasing into the metrical scheme. The caesura may coincide with conventional punctuation marks, as in the following Shakespearean line, in which a strong pause is demanded after each comma for rhetorical expression: This blessed plot,this earth,this realm,this England,