Tied the knot is an idiom that refers to the act of getting MARRIED. WED (3 letters) is a shortened form of the word 'WEDDING', which is the ceremony in which two people are united in marriage. WEDDED (6 letters) is another way of saying 'MARRIED' or 'united in marriage'. MARRIED (7 letters) is the state of being united to another person in a legally recognized and sanctioned union. Saidido (7 letters) is a phrase used in some cultures to signify the completion of a marriage ceremony. All of these terms refer to the same act of getting MARRIED, and together they provide a comprehensive description of the phrase 'tied the knot'.