sharpen

Etymology

From Middle English scharpenen, scharpnen, equivalent to sharp + -en.

verb

1. (transitive, sometimes figurative) To make sharp.
   to sharpen a pencil or a knife or a musical note
   The use of algorithms in policing is one example of their increasing influence on our lives.[…]who, if anyone, is policing their use. Such concerns were sharpened further by the continuing revelations about how the US National Security Agency (NSA) has been using algorithms to help it interpret the colossal amounts of data it has collected from its covert dragnet of international telecommunications. 2013-07-26, Leo Hickman, “How algorithms rule the world”, in The Guardian Weekly, volume 189, number 7, page 26
2. (intransitive) To become sharp.