The word disciplinable implies that someone has displayed behavior that requires correction or punishment. While the word is not frequently used in everyday conversation, there are several synonyms that can convey the same idea. For example, the word punishable is a common synonym. Other options include correctable, reprimandable, and amendable. These words all suggest that someone has done something wrong and needs to be disciplined in some way. Other potential synonyms might include teachable, coachable, or moldable, depending on the context and the specific type of behavior that needs to be corrected.