Filum aquae
Defined in 3 dictionaries — Ballentine's (1916), Black's (1910), Stimson (1881)
Ballentine's Law Dictionary
James A. Ballentine · 1916
The thread or center line of the stream. See 21 Mass. 268, 16 Am. Dec. 342.
Black's Law Dictionary
Henry Campbell Black, M.A. · 1910
A thread of water; a line of water; the middle line of a stream;of water, supposed to divide it into two equal parts, and constituting in many cases the boundary between the riparian proprietors on each side. Ingraham v. Wilkinson, 4 Pick. (Mass.) 273, 16 Am. Dec. 342.
Defined under Filum in Black's Law Dictionary.
Glossary of Technical Terms, Phrases, and Maxims of the Common Law
Frederic Jesup Stimson · 1881
I. (The thread of the water.) The water line or edge; the middle line of a stream. Filum viae: the middle line of a street. Pin,^. End. En fin, al fine: at last, at the end.