Dying declaration is an exception to the rule against hearsay evidence. It refers to statements made by a dying person about the cause of their death. It is considered reliable because the maxim is that a person would not lie as they are dying and facing their maker. For a dying declaration to be admissible, it must relate to the cause of death, be made by a competent person, and not be inconsistent, doubtful, influenced, or untrue. Dying declarations can be written, verbal, through gestures, or nods and are given evidentiary value in court.