floodmark

floodmark

(ˈflʌdˌmɑːk)
n
(Physical Geography) a high-water mark
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in classic literature ?
It was one of those dangerous moments when speech is at once sincere and deceptive; when feeling, rising high above its average depth, leaves floodmarks which are never reached again.