| ATR | the upper chamber of each half of the heart |
|---|---|
| ATR | the right upper chamber of the heart that receives blood from the venae cavae and coronary sinus |
| ATR | the upper chamber of each half of the heart |
| ATR | the left upper chamber of the heart that receives blood from the pulmonary veins |
| ATR | provoking horror |
| ATR | exceptionally bad or displeasing |
| ATR | shockingly brutal or cruel |
| ATR | in a terrible manner |
| ATR | to an extravagant or immoderate degree |
| ATR | the quality of being shockingly cruel and inhumane |
| ATR | an act of atrocious cruelty |
| ATR | the quality of being shockingly cruel and inhumane |