[n] a break or pause (usually for sense) in the middle of a verse line
[n] a pause or interruption (as in a conversation); "after an ominous caesura the preacher continued"
A caesura, in poetry, is an audible pause that breaks up a line of verse. This may come in the form of any sort of punctuation which causes a pause in speech; such as a comma; semicolon; full stop etc. It is also used in musical notation as a complete cessation of musical time.
Arma virumque cano, || Troiae qui primus ab oris
("I sing of arms and the man, who first from the shores of Troy. . .")
Cynthia prima fuit; || Cynthia finis erit.
("Cynthia was the first; Cynthia will be the last" — Horace)
Hwæt! we Gar-Dena || on geardagum
("Lo! we Spear-Danes, in days of yore. . .")
break, inflection, intermission, interruption, pause, prosody, suspension