sharp ‧ en /ˈʃɑːpən $ ˈʃɑːr-/ BrE AmE verb
[ Word Family: noun : ↑ sharpener , ↑ sharpness , ↑ sharp ; adverb : ↑ sharp , ↑ sharply , ↑ sharpish ; verb : ↑ sharpen ; adjective : ↑ sharp ]
1 . [intransitive and transitive] to make something have a sharper edge or point, or to become sharper:
Anne sharpened her pencil and got out her homework.
2 . [transitive] to make a feeling stronger and more urgent:
A series of attacks have sharpened fears of more violence.
3 . [transitive] ( also sharpen something ↔ up ) to improve something so that it is up to the necessary standard, quality etc:
The course will help students sharpen their writing skills.