noun which may take the genitive case particle 'no', noun
unfinished; half-written; drafted
Describes something that has been started but not completed, especially letters, manuscripts, or other written works. Often used as a noun modifier with の.
机の上に書きかけの手紙がある。
There is an unfinished letter on the desk.
書きかけの原稿を保存して、明日続きを書く。
I'll save the half-written manuscript and continue writing it tomorrow.
未完成 is a more formal term for 'incomplete' or 'unfinished', often used for projects or works, while 書きかけ specifically refers to something that has been started in writing but not finished.
Compound of 書き (kaki, the continuative form of 書く 'to write') + かけ (kake, the continuative form of 掛ける 'to start doing something and leave it unfinished').