#whirlpool

• Deep pool — A popular or regional name attributed to a deep spot in a river or lake, where the water forms whirlpools and there is a risk of sinking; sometimes used to denote a tool or weight utilized to submerge fishing nets or other technical devices underwater.
• Deep river pool — A rare regional noun used in certain dialects of northwestern Transylvania to designate a deep pool, a dangerous whirlpool in a riverbed, or a small muddy pond left in a depression after floods recede; by extension, a marshy ground.
• Whirlpool — A circular and turbulent movement of a fluid, primarily encountered in hydrography as a powerful water whirlpool forming in rivers, in areas where the main current strikes an obstacle, a bend in the bank, or undergoes a sudden shift in depth. This structural hydrodynamic phenomenon creates a downward suction zone dangerous for navigation and swimming, generated by the intersection of water filaments with different speeds and directions.
• Water hollow — An archaic form or rare regional variant used in certain ancient dialects to describe a deep water hollow, a dangerous whirlpool, or a deep pool formed along the course of a large river. Figuratively, the term can evoke an abyss, a chasm, or a chaotic and impenetrable situation where things are lost without a trace.