q.t.
noun (in phrase on the q.t.) informal
Secretly; secret: Brenda nipped round on the q.t. please, I beg you, regard this for the present as on the q.t....
- We used to keep the inhalers in our coat pockets, on the q.t.<em/>
- The guns are on the q.t. now, thank God for that, and we hope and pray that they do not start again.
- ‘This was on the q.t. and simply part of the graft that goes with the job,’ he wrote to his mother.
Origin
Late 19th century: abbreviation of quiet.