IPA: //mɪsˈtruːθ//
KK: /ˈmɪsˌtruːθ/
A statement that is not true; a lie or falsehood.
He was caught telling a mistruth about his whereabouts last night.
Mistruth → It is formed from "mis-" (meaning wrongly or badly) and "truth" (from Old English "triewð", meaning fidelity or faithfulness). The word "mistruth" refers to a statement that is wrongly presented as the truth or a falsehood.
Think of 'mis-' meaning wrongly, and 'truth' referring to what is real. This helps you remember that 'mistruth' means something that is wrongly claimed to be true.