low point

noun3

1. •
   A nadir; the time when things are at their worst.
2. •
   The lowest position that something attains.
3. •
   The Ancient Greek punctuation mark ., sitting on the baseline, lower than the middle point and the high point, used for a medium pause.

   • The Tours scriptorium, however, in the ninth century, still used the high point for periods and the low point for a lesser pause. — 1964