Turn cap

a sort of chimney cap which turns round with the wind so as to present its opening to the leeward.

See also: Turn

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
The low-profile flasks are accessible with a 10-mm pipette and small scrapers and also feature one-half turn cap closures for improved lab efficiency.
It will be very challenging because there is so much competition for property, but I will continue to be very active, certainly we are not resting." Moinian's ability to continue building his real estate empire at such an impressive clip isn't simply a function of low interest rates, but his phenomenal ability to turn cap rates around.
Markets dread inflation for it has the potential to push up interest rates in the economy, which in turn caps economic growth.