Answer: honing

AnswerCrossword Clue
HONINGMaking dull knives sharper
HONINGRefining, as one's skills
HONINGGiving an edge to
HONINGUsing a whetstone
HONINGImproving, in a way
HONINGSharpening
HONINGFunction of a strop.
HONINGSharpening.
HONINGImproving the edge
HONINGPerfecting
HONINGFine-tuning
honingto sharpen to a fine edge
honingHONE, to sharpen (to make sharp (capable of cutting or piercing))