The successful and powerful Mongolian raids came to a halt at the end of the 14th century following Timur's leadership in a world of growing Western dominance. The Renaissance understanding of "nomad" would have been an active one based on conquering attacks of Mongul nomads on what is referred to as "sedentary" civilized European cities.
At the time of the Mongol raids of the 13th century, beginning with Genghis (also Chinggis) and ending with Timur (who died in 1405 though raids continued until the mid-1400s), Asian nomads were understood to be people living on the unforgiving steppes, herding sheep, following the seasons, going south in cold times and north in warm times, hunting, and, in a sense, living on their horses backs. They were formidable in war as a result because nothing could daunt them while charging in attack and shooting arrows from their shortbows from atop their horses without breaking the horses stride.
In Marlowe's Tamburlaine the Great, Tamburlaine is introduced in an exchange between Mycetes and Meander. Mycetes describes him as one that, as "a fox in midst of harvest-time, / Doth prey upon my flocks of passengers ...." Meander further describes him as a thief that robs while committing "outrages":
MEANDER. Tamburlaine, that sturdy Scythian thief,
That robs your merchants of Persepolis
Trading by land unto the Western Isles,
And in your confines with his lawless train
Daily commits incivil outrages,
This description accords with the way Mongolian nomads were experienced and with how they were described. Thus it seems logical to say that Renaissance people understood Tamburlaine to be a nomad through his ethnic origins, though his tribal lifestyle of shepherding from atop horseback, and for violent raids and attacks against sedentary civilized cultural cities.