1. upgradient - Adjective
2. upgradient - Adverb
A position up along a gradient from a starting position.
(hydrology) a location that is the source groundwater for another location; similar to upstream.
Uncontaminated groundwater is found upgradient of a contamination source.
The reverse direction along a gradient.
(hydrology) a direction that groundwater flows from.
Source: en.wiktionary.org