Tongue and groove is a phrase that describes a common woodworking technique where two pieces of wood are joined together with interlocking tongues and grooves. Some synonyms for this term could include locking, interlocking, dovetail, jointed, and fitted. These terms all describe the same concept of two pieces of wood fitting perfectly together, creating a secure and seamless join. These terms can be used interchangeably depending on the specific context and the preference of the speaker or writer. Using these synonyms can add variety to written or spoken language and keep the conversation interesting and engaging.