The only free and comprehensive online etymological dictionary of the Spanish language
Barrio (2) m. (Surname) meaning unknown (possibly "the countryside," "the new place")
Of uncertain, but probably Basque origin, as the surname is endemic to Basque people and the ending -o looks like the locative suffix. Perhaps meaning "the countryside" or "the new place," from Barri with the locative suffix -o. (See Barri for an explanation of the debate surrounding this word's origin.)

The belief that the surname is from barrio (1) in the sense of "neighborhood" is an old myth from folk etymology.
basa f. (Noun) "column"
13th cent. Originally meaning "base." From Latin basa "foundation." For a continued etymology, see base.
base f. (Noun) "base"
Early 18th cent. borrowing from Latin basis 'id.' It replaced the older word basa, now restricted to architecture. Borrowed from Ancient Greek βάσις ‎(básis) "base," but also "step." From Proto-Indo-European *gwh2-ti̯- "gone." From a root *gweh/2- "to go." See also venir.
Latin venire "to come"
Gothic qiman "to come," Old Norse kuma 'id.,' Old Saxon kuman 'id.,' Old High German cuman 'id.,' Old English cuman (English come)
Sanskrit gáti "going," Young Avestan jasaiti "to move"
A kum-, B käm-
bastante (Adverb) "enough"
Early 14th cent. From bastar and adverb-forming suffix -ante.
Asturian (dialects) bastante, Portuguese bastante, Galician bastante, Catalan bastant, Italian abbastanza (< a bastanza)
bastar (Verb) "to suffice"
13th cent. From Vulgar Latin *bastare "to carry," from Ancient Greek βασάζειν (basázdein) "to lift," "to carry." Ultimately of unknown origin.
Asturian bastar, Portuguese bastar, Galician bastar, Catalan bastar, French baster, Italian bastare
Latin basterna (?) "litter to carry a person"
bastardo m. (Noun) "bastard"
14th cent., although an attestation with an uncertain meaning is found in the early 13th cent. Borrowed from Old French bastard 'id.' From bast "concubinage," of unknown origin, with the pejorative suffix -ard added (for the continued etymology of which, see its cognate suffix -ardo).
"Differing proposals for the root of 'bastard' abound. The notion is posited that a Germanic root *bast 'marriage' is the origin, with the pejorative suffix -ard added to mean it was the child of a 'bad' marriage with a wench of low estate or that a bastard was the peasant offspring of a Christian and a pagan, a conjointure not sanctioned by holy ritual. But that guess reads to me as a conceit no sillier than a paddlesack one." B. Casselman, At the Wording Desk (2016)
basura f. (Noun) "trash," "refuse," "garbage"
12th cent. From Vulgar Latin *vesura, from Latin versura "swept," from verrere "to sweep" (see barrer).
Asturian basura, Aragonese basuera
batalla f. (Noun) "battle"
13th cent. Borrowed from Old Occitan batalha, from Vulgar Latin *batallia 'id.' From Latin battualis "fighting," from battuere "to beat" (see batir).
Also the origin of the surname Batallas, originally given to especially gifted fighters and knights who attempted and achieved an act of heroism on the field of battle.
batir (Verb) "to beat"
12th cent. From Late Latin battere 'id.,' from earlier Latin battuere. Said to be from a Celtic source, probably Gaulish (compare Welsh bathu "beat"). From Proto-Celtic *bat-we/o- 'id.' From Proto-Indo-European *bhed- "to hit."
Ultimately from Proto-Indo-European *bheu̯d- "to strike," from the root *bheu̯- 'id.' See also botar.
Asturian bater, (dialects) batir, Portuguese bater, Galician bater, Catalan batre, French battre, Italian battere, Aromanian bat, Romanian batter
bebé m. (Noun) "baby"
Borrowed from French bébé 'id.' Of uncertain origin.