Lowest is often used to describe something that is the worst or the bottom.

Neymar has the lowest pain threshold of any player in World Cups since Opta stats began.

— Gary Lineker 💙💛 (@GaryLineker) July 2, 2018

being ridiculed for having the lowest uber rating at the dinner table

— michael clifford (@Michael5SOS) July 12, 2017

Attention CEOs:

I'm one of you. In 2015 I made 33x more than our lowest-paid employee.

I took a big pay cut & raised our minimum wage to $70k. Now our top exec makes 4x more than our lowest-paid employee.

In that span, our business tripled. Amazing what happy employees can do.

— Dan Price (@DanPriceSeattle) December 26, 2019

Did you mean low-test?