versant

A gadget lover, Alexander is known to roll up his sleeves to become versant with the latest security technologies.

From Reuters ● May 26, 2013

Llan means a level place generally, as most of your readers who are versant in those subjects know.

From Notes and Queries, Vol. IV, Number 110, December 6, 1851 A Medium of Inter-communication for Literary Men, Artists, Antiquaries, Genealogists, etc. by Various

The fact that the lavas of Vesuvius have broken out on the southwestern side, while the old wall of the cone has remained unbroken on the eastern versant, has a curious explanation.

From Outlines of the Earth's History A Popular Study in Physiography by Nathaniel Southgate Shaler

The Kayan or Bulungan river is the only other in the eastern versant that calls for mention.

From Encyclopaedia Britannica, 11th Edition, Volume 4, Slice 3 "Borgia, Lucrezia" to "Bradford, John" by Various

For this purpose, they gave orders to Diego Garcias de Alfaro, an inhabitant of Lima who was versant in maritime affairs, to repair and fit out the two barks which had drifted on shore.

From A General History and Collection of Voyages and Travels - Volume 05 Arranged in Systematic Order: Forming a Complete History of the Origin and Progress of Navigation, Discovery, and Commerce, by Sea and Land, from the Earliest Ages to the Present Time by Robert Kerr