Of, relating to, or found in a river or rivers; produced by river action.
From Latin fluvius (river, from fluere to flow) + -al (adjectival suffix). The Latin root fluere also appears in fluid and fluent, all sharing the concept of flowing water.
Geologists love the word 'fluvial' because it's precise—instead of saying 'made by rivers,' they can pinpoint the exact process. It's how scientists compress complex ideas into single technical terms.
Complete word intelligence in one call. Free tier — 50 lookups/day.