sharpen UK /ˈʃɑːpən/US /ˈʃɑɹpən/verb 2forms 5phrases 1 verb2 •To make sharp.He that wrestles with us strengthens our nerves and sharpens our skill. — 1790 •To become sharp. formssharpened · sharpening · sharpeneth · sharpens · sharpenest Phrases with sharpen sharpen upTo become sharp (in all senses).