lower limit

n.

1.

the limit on the lower (or southernmost) side of something.

Thesaurus

Noun	1.	lower limit - the smallest possible quantity       minimum peak, extremum - the most extreme possible amount or value; "voltage peak" small indefinite amount, small indefinite quantity - an indefinite quantity that is below average size or magnitude skeleton - something reduced to its minimal form; "the battalion was a mere skeleton of its former self"; "the bare skeleton of a novel"
	2.	lower limit - the limit on the lower (or southernmost) side of something demarcation, demarcation line, limit - the boundary of a specific area