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

He was well versant in military affairs and took great delight in war, of which he endured the labours and privations with much patient fortitude.

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 Kerr, Robert

The one great river of the eastern versant is the Kutei or Mahakan, which, rising in the central mountains, flows east with a sinuous course and falls by numerous mounts into the Straits of Madassar.

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

The rivers of the southern versant are waters of capacious drainage, the basin of the Kahayan having, for instance, an area of 16,000 sq. m., and the Barito one of 38,000 sq. m.

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

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