lean into the corner

All one expects of the word at the end of a line is that it holds the corner.

rough edge

The right margin of line endings competing with the deckle edge of the page.

line relationship

Finally, no particular line is valuable except inasmuch as it performs a dramatic function in relationship to other lines in a particular poem: one kind of line ending becomes powerful because of its relationship to other kinds of line endings.

—James Longenbach, The Art of the Poetic Line (Graywolf 2008)