1. something true which brings distress, something which is upsetting
it is/was a sad truth for him/her to take/accept/swallow, face/face up to the sad truth
The sad truth is an expression used to say something is a regrettable or upsetting reality. This phrase shows the speaker's feelings towards the rest of the information they are about to deliver or the facts they are sharing. You might use it to deliver bad news: "The sad truth is we can't afford to keep as many staff as we used to"; or to express an attitude of regret towards the facts: "The reality that 5,000 children are homeless is a sad truth we need to address". This is a formal expression used both in professional and social contexts.