Enjambment
The sentence overflowing past the line's end, continuing into the next line without syntactic pause.
Enjambment occurs when the sentence doesn't stop at the line's end and pours into the next: syntax strides over the metrical border. The line ending stays marked (by the eye, by rhyme if any), but meaning forces the passage — two logics superimpose and create tension.
That tension is expressive: enjambment can mimic momentum, overflow, falling, or suspend a word at the line's edge to charge it with expectation. Its short forms have proper names in French prosody: the rejet (the short element thrown to the next line's start) and contre-rejet (the short element anticipating at line's end). Routine in free verse, enjambment remains its main carving tool: choosing where to break the line is choosing what the eye isolates.
Example
"so much depends / upon // a red wheel / barrow"