1. Noun

   only this; this much

   Usually written using kana alone

2. Noun, Noun which may take the genitive case particle 'no'

   (this) small amount; (such a) paltry amount; only this much; slightest bit

   Usually written using kana alone

3. Noun

   (not) in the slightest; (not) at all

   Usually written using kana aloneas こればかりも with neg. verb

Also written 是許り【こればかり】korebakari、此許り【こればかり】korebakari