hard to swallow

Hard to swallow is an idiom which is speaking of something, such as an idea or concept which is very hard to believe or to acknowledge. This is usually in reference to a thought, idea or action that is so awe-inspiring it is just hard for you to understand the practicality of it and wrap your head around the idea. If something is hard to swallow, you may understand it might be factual, but cant help deny its validity.