N3
かけ
Half-, Not yet finished, About to, Begin to
俺の食べかけだけど大丈夫?
This is half-eaten by me, is that okay?
Explanation
「かけ」 has 2 uses
1Half-done
An action stopped halfway: 「食べかけのパン」 (half-eaten bread), 「読みかけの本」 (a book you're partway through), 「言いかけてやめた」 (started to say something and stopped).
食べ掛けのケーキでも良ければありますよ。
I have some half-eaten cake, if you would like.
俺の食べかけだけど大丈夫?
This is half-eaten by me, is that okay?
2About to / nearly
Something is about to reach a state, or nearly did: 「壊れかけの時計」 (a watch about to break), 「死にかけた」 (nearly died).
彼は死にかけの子犬を救った。
He saved a puppy that was close to death.
彼女は壊れかけのパソコンを買って直すのが趣味だ。
Her hobby is buying computers that are about to die and fixing them.
Mixed up with
「食べかけのパン」: bitten into and not finished; 「焼きたてのパン」: fresh out of the oven; 「食べ切った」: ate it all.
Before a noun you need 「の」: 「食べかけのりんご」. This is a common fill-in-the-blank point.