Repeating something twice (تَثْنِيَةٌ)
أصول الفقه
المعنى الاصطلاحي :
Repeating the words of Adhān (call to prayer), and saying it twice.
التعريف اللغوي المختصر :
"Tathniyah": joining one to another one. Other meanings: making one thing into two, repeating something twice.