caravanserai n.

1590s, in reference to in North Africa or western Asia, "company of travelers, pilgrims, merchants, etc., going together for security," from French caravane, from Old French carvane, carevane "caravan" (13c.), or Medieval Latin caravana, words picked up during the Crusades, via Arabic qairawan from Persian karwan "group of desert travelers" (which Klein connects to Sanskrit karabhah "camel").

Used in English for "any large number of persons traveling together with much baggage" (1660s), hence "a large covered carriage for conveying passengers" (1670s)  or later for traveling shows or used as a house by Gypsies. In modern British use (from 1930s), often a rough equivalent of the U.S. camper or recreational vehicle.

*terə- Proto-Indo-European root meaning "cross over, pass through, overcome."

It forms all or part of: avatar; caravanserai; nectar; nectarine; nostril; seraglio; thrill; thorough; through; tranche; trans-; transient; transom; trench; truculent; truncate; trunk.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit tirah, Avestan taro "through, beyond;" Latin trans "beyond;" Old Irish tre, Welsh tra "through;" Old English þurh "through."