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-a Feminine suffix

From Latin -a, from Proto-Italic *, from late Proto-Indo-European *-(e)h2, from Proto-Indo-European *-h2, a suffix indicating collective and abstract animate nouns, from Pre-Proto-Indo-European *-h2, a suffix indicating plurale tantum.

Romance: Western Vulgar Latin: Asturian -a (rarely -e), Portuguese -a, Galician -a, Catalan -a, French x, Italian x Eastern Vulgar Latin: Romanian x

In Pre-Proto-Indo-European, a suffix *-h2 was used to form plurale tantum nouns out of collective nouns (e.g., "waters" from "water"). This was attached to the vowel stem *-e-, *-i-, *-u- and *-0- to form *-eh2, *-ih2, *-uh2, and *-h2. The four different endings all to express a single idea of plurality would not last. But now we must discuss the historic Proto-Indo-European method for feminizing words.

In Proto-Indo-European *sor "woman" was added as a suffix to animate nouns (preserved in Anatolian but also as a fossil in a smattering of non-Anatolian words, like Spanish sor. Linguists do not precisely agree as to why *-sor as a feminine marker was gradually replaced by the *-(e)h2 collective suffix.

Most recent theories involve the suffix playing an "individualizing" role. As a collective/abstract suffix *-(e)h2 referred to a subset of larger mass nouns (returning to the example "waters" (collective) versus "water" (mass), the "waters" is plural but refers to a subset of all "water"). Over time, the dependence on *-(e)h2 to refer to a subset of a broader category began to individualize the subject. By the late Proto-Indo-European period *-(e)h2 was heavily used, and stood in contrast to the typical animate ending *-s. *-(e)h2 acquired a new sense of "the other."

In compelling support of this theory, a word that looks to be a relic from the transition period from collective/abstract suffix (as preserved in Anatolian and in some Core Indo-European fossils) to a feminine suffix (the familiar -a in Core Indo-European). The Proto-Indo-European word *h2u̯idhéu̯eh2- "widow" (animate in Anatolian and feminine in late Proto-Indo-European), looks built off of *h2u̯idhéu̯o- "belonging to the one fatally struck." Thus the original sense of a widow would have been "the one of whom was fatally struck," then later "the bereaved," and finally "the female bereaved." See Luraghi (2011), Tichy (1993), and Melchert (2014b) for a broader discussion.
a (Adverb) "at," "in"

A post-Latin development from the 12th cent., deriving from Latin ad "to," "toward." From Proto-Italic *ad 'id.' From Proto-Indo-European *h2ed 'id.'

Romance: Western Vulgar Latin: Asturian a, Portuguese a, Galician a, Catalan a, French à, Italian a, ad; Eastern Vulgar Latin: Romanian a

Italic: Oscan az "by" (ad-s)

Indo-European: Celtic: Welsh â; Germanic: Gothic at, Old Icelandic at, Old English æt (English at)
ab- Prefix indicating "off" or "away"

Not a productive prefix in Spanish, it occurs as a relic in verbs like abrir. From Latin ab 'id.' From Proto-Italic *ap- 'id.' From Proto-Indo-European *h2epo 'id.' As an allative preposition, the word had a full grade in ab- and a zero grade *h2po, preserved in po-.

Italic: Umbrian ap-, Paelignian af-, Oscan af-

Indo-European: Germanic: Gothic af, aff-, Old Norse af, Old High German aba, Old Saxon af, English of; Balto-Slavic: Lithuanian po-, Latvian ap "beneath," Old Church Slavonic po, Russian po; Albanian: pa "without;" Hellenic: Ancient Greek ἀπό (apó) "far from;" Indo-Iranian: Sanskrit ápa "away," Avestan apa-; Anatolian: Hittite appā "behind"
abajo (Adverb) "down," "below"

First attested c. 1300 but was rarely used until the 15th cent. Formed from Latin a(d)- "at," "toward" and bassus "down" (see a- and bajo respectively).

Also the origin of the surname Abajo, given to Moorish families that lived in the lowlands of Spain.

Romance: Asturian (Teberga) abaxu, Portuguese abaixo, Galician abaixo, Catalan abaixo, French à bas
abierto (Adjective) "open"

12th cent. From Latin apertus 'id.,' from aperire "to open." See abrir.
-able, -ible Prefix indicating ability or inclincation.

From Latin -abilis and -ibilis, of identical meanings, both from an a-stem and an i-stem fixed to -bilis "capability." From Proto-Italic *-þli- 'id.' From the Proto-Indo-European instrumental suffix *-dhli-.
abogado (Noun) "lawyer," "advocate," "counsel"

13th cent. From Latin advocatus "aide," "advocate," "witness." From advocare "to advocate" (see abogar).

Historically, la abogada typically meant "interceding saint" and when used for "lawyer" was an insult, as the profession of advocate was exclusive to men prior to the 1960s.

Romance: Western Vulgar Latin: Asturian abogáu, Portuguese advogado, Catalan advocat, Old French avocat, Italian avvocato, Dalmatian abucat; Eastern Vulgar Latin: Romanian a(d)vocat
abogar (Verb) "to plead"

13th cent. From Latin advocare "to summon." From ad- "toward" (see a-) and vocare "to call." Vocare is a verb derived from vox "voice" (see voz).

Romance: Western Vulgar Latin: Asturian abogar, Portuguese advogar, Catalan advocar, French avouer, Italian avvocare
abrir m. (Noun, Verb) "opening;" "open"

12th cent. From Latin aperire "to open." From Proto-Italic *ap-wer-je- 'id.' The first element *ap- is from *h2ep- "off," "away" (see ab-); the rest is from Proto-Indo-European *h2u̯er-i̯e/o- "to cover." A primary i̯e/o-present.

Romance: Western Vulgar Latin: Asturian abrir, Portuguese abrir, Catalan obrir, French ouvrir, Italian aprire; Eastern Vulgar Latin: Aromanian apir; Sardinian: abbèrrere
absolutamente (Adverb) "absolutely"

From absoluto and -mente, an abverb-forming suffix.