An accusation was a claim made by someone or something (the accuser) that an individual (the accused) had committed a fault or a crime. Evidence discovered in an investigation could be used for supporting or backing up an accusation. A false accusation, also known as a baseless accusation or unfounded accusation, was an accusation made by someone or something which was proven not to be true and/or was unsupported by the facts. (TOS: "Court Martial", "All Our Yesterdays"; TNG: "Sins of The Father", "Transfigurations"; DS9: "Dax", "Cardassians", "Covenant"; VOY: "Retrospect"; ENT: "Civilization")
After uttering a false accusation, an individual might apologize to the offended party. (TNG: "Encounter at Farpoint"; ENT: "A Night in Sickbay")
In a situation where four strangers were abducted and confined to a small room, they might become suspicious of each other. There would be false accusations against one or more of them being in collaboration with the abductors, creating hostility between the strangers which could lead to violence and ending with their suspicions destroying them. (TNG: "Allegiance")
In 2267, on planet Gothos, Captain James T. Kirk was accused by the entity Trelane of the "high crime of treason against a superior authority, conspiracy, and the attempt to foment insurrection." (TOS: "The Squire of Gothos")