There are multiple definitions:

1. Terrence Higgins Trust(English)

2. Tagger's hybrid technique(English)

   • refers to thermomechanical compaction
   • Dentistry
   • https://doi.org…91.2012.02039.x

3. total hypopnea time(English)

   • AHI, BMI, NREM, OSA, REM, TAHT, TAT
   • Respiratory system, Sleep medicine, Pathology
   • https://doi.org…eep.2021.02.020