sharpen
v.v. to make the edge or point of something thin and sharp so it cuts better. You can also use it to describe improving a skill or making an image look clearer.
v. to make an edge or point acute or fine; to improve the acuity of a sense or the proficiency of a skill. Transitive — requires a direct object.
I need to sharpen my pencil before the exam starts.
The chef uses a whetstone every morning to sharpen his knives for the busy lunch service.
The intensive three-month internship helped her sharpen her analytical skills, allowing her to identify subtle market trends that her more experienced colleagues had overlooked.
From Middle English scharpenen, scharpnen, equivalent to sharp + -en.
The verb is transitive and takes a direct object. It is frequently used metaphorically with nouns like 'skills', 'focus', or 'wits'.