ETYMOLOGY OF THE SURNAME TREVIÑO
TREVIÑO (Spanish; with the /n/ properly having a tilde [wavy bar] above it or 'ñ') means 'dweller near a boundary stone touching three districts'. A Castilian name from the mountains of Burgos; Treviño, town in northern Spain at 42.44 N 2.45 W, just south of the Basque-speaking area. The former part tre- means 'three'; the latter part -viño is obscure in meaning, but the accepted etymology is "stone boundary", which matches Spanish fin 'end' from Latin finis (with the first /i/ being long) 'boundary, limit, border; territory; term, limit; end'. This usage with finis is a better match than the similar-sounding Spanish viña, 'vineyard' because the /f/ in finis can become a voiced reflex /v/ between vowels and the long Latin /i/ can palatalize the /n/ to form /ny/ or /ñ/, thus Tre-viny-o, with masculine /o/. Also that area is known to be situated at the juncture of three regions.
(First source: Elsdon C. Smith: New Dictionary of American Family Names, New York, 1973, Harper & Row; with many modifications compiled from other sources by Carl Masthay; October 1998)