(language education, uncountable) Initialism of teacher talking time: the amount of time a teacher talks during a class. / (cycling) Initialism of team time trial.

Initialism of twin-to-twin transfusion syndrome. / Initialism of tonic tensor tympani syndrome.

(Internet slang) Initialism of to tell the truth.

Initialism of to the tune of: indicating the piece whose melody is borrowed for a new song.

Initialism of Thomas the Tank Engine.