· Still water or stagnant water is water that has been left sitting for long periods of time, promoting the growth of biofilm, bacteria and fungi, making it dangerous to drink or swim in. · The meaning of STILLWATER is a part of a stream where no current is visible. · The StillWater meme is an ironic TikTok trend that uses the text “stillwater” as a caption on a benign amount of water to pretend it is scary or harmful. Definition of 'stillwater' stillwater in American English noun a part of a stream that is level or where the level of inclination is so slight that no current is visible Why is everyone on TikTok talking about "stillwater" and what makes it so dangerous? The trend originated from a series of urban explorer videos where the explorers encounter stagnant water... · (countable) A serving of stillwater. STILLWATER definition: a part of a stream that is level or where the level of inclination is so slight that no current is visible. See examples of stillwater used in a sentence. · (countable) A serving of stillwater. STILLWATER definition: a part of a stream that is level or where the level of inclination is so slight that no current is visible. See examples of stillwater used in a sentence.