Definition of "sharpen"

sharpen

/ˈʃɑɹpən/

verb
third-person singular simple present sharpens, present participle sharpening, simple past and past participle sharpened
1. (transitive, sometimes figurative) To make sharp.
  Quotations
  He that wrestles with us strengthens our nerves and sharpens our skill.
  1790 November, Edmund Burke, Reflections on the Revolution in France, and on the Proceedings in Certain Societies in London Relative to that Event. […], London: […] J[ames] Dodsley, […]
  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 July 26, Leo Hickman, “How algorithms rule the world”, in The Guardian Weekly, volume 189, number 7, page 26
2. (intransitive) To become sharp.