An enjambment is the opposite of another poetic term starting with the letter “e” – the end-stop. Whereas end-stopped describes a metrical line ending at a grammatical boundary or break (think dash, period, parenthesis, colon, or semicolon), an enjambment works more like a run-on sentence, adding fluidity to the rhythm.
“The running-over of a sentence or phrase from one poetic line to the next, without terminal punctuation.”
In the kid lit arena, Shel Silverstein offers some excellent examples of enjambment. “Invitation” from Where the Sidewalk Ends is one of my favorites.