a worker who makes or adds the top to something
"The hat factory hired a skilled topper to finish each fed by hand-stitching the crown onto the brim."
a worker who cuts tops off (of trees or vegetables etc.)
"The farmer hired an experienced topper to trim the excess leaves from the carrots before they went into storage."
an exceedingly good witticism that surpasses all that have gone before
"After we shared a dozen jokes, Sarah's final punchline was such a sharp topper that everyone stopped laughing in shock."
a woman's short coat
"She pulled her wool topper on before stepping out into the freezing wind."
Something that is on top.
"She slipped a decorative bow onto the hat as the final topper before handing it over."
A surname.
"When I asked Mr. Topper for directions, he kindly pointed me toward the post office on Main Street."