Boiarin

And taking counſell with the Boiarins, at that time remayning with Suiskey [i.e., Vasili IV Ivanovich Shuisky] in the chiefe Citie, we ſent our Meſſengers to his Maieſtie at that time, being at Smolensko, viz. Michael Salticoue, and others, requeſting that his Maieſtie would grant vs his Sonne to be our Lord. […] How the Boiarins handled other Gentlemen, and principall perſons of the Ruſſe Religion, although more inclined vnto them: but eſpecially the Officers and Seruants of the Wors, as alſo ſuch as had fled over.

Source: wiktionary

JOHN M[ILTON] THAYER—Something of a boiarin; a physical and intellectual autochthon, but not exolete by over use.

Source: wiktionary

“Our travelers,” he [Mikhail Pogodin] wrote, “were captivated only when the Russian spirit was realized before their eyes, when they saw the way our pretty Russian girls and our fine fellows (molodtsy) were dressed. They appeared before us in their grandfathers’ kaftans—staid boiars, majestic boiarins. What delight, what splendor, what variety, what beauty, what poetry!”

Source: wiktionary