The only free and comprehensive online etymological dictionary of the Spanish language
cacho (3) m. (Noun) (Latin America) "horn;" (Colombia) "(marijuana) joint;" (Chile) "huckster;" (Ecuador) "humorous anecdote"

19th cent. Probably a term developed from cacho (4) "droopy," which can mean downward-facing horns. However, Corominas (1987) believes the origin is likely in cacho (1) today meaning "piece" but in antiquity meaning "pot," because a horn can hold liquid like a pot. This is less convincing when viewed from a historical and technological perspective: horns were not vessels of liquid themselves but the nozzles, fixed to the mouth of a leather bota bag.

Romance: Western Vulgar Latin: Portuguese cátulo
cacho (4) (Adjective) "droopy" (especially of cattle horns)

From Latin coactus "joined together," from cogere "to assemble." From con-, a perfectizing prefix, and agere "to do" (see -igar).
cacho (5) (Noun) (Andalusia) "hit;" (Salamanca) "profound sentimentality"

Both the Andalusian and Salamancan meanings are said by Tibón (1988) to be from Vulgar Latin cacculus "small thing," "pot," but originally meaning "pottery sherd;" but the semantic evolution seems obscure. For a continued etymology of cacculus, see cacho (1).
cada (Preposition) "each," "every"

10th cent. From Latin cata "by," from Ancient Greek κάτα (káta) "concerning;" "downwards." From Proto-Indo-European *km̥t- "down"

Romance: Western Vulgar Latin: Asturian cada, Portuguese cada, Galician cada, Catalan cada; Eastern Vulgar Latin: Romanian câte

Indo-European: Anatolian: Hittite kattan "below"
caer (Verb) "to fall"

10th cent. From Latin cadere 'id.' From Proto-Italic *kad-e/o- 'id.' From Proto-Indo-European *ḱh2d- 'id.'

Romance: Western Vulgar Latin: Asturian cayer, Portuguese cair, Galician caer, Catalan caure, French choir, Italian cadere; Eastern Vulgar Latin: Aromanian cad, Romanian cădea

Indo-European: Hellenic: Ancient Greek κεκαδών? (kekadón) "robbing;" Indo-Iranian: Sanskrit śad- "to fall"
café m. (Noun) "coffee"

Early 18th cent. From Italian caffè, from Turkish kahve, from Arabic qahwa, possibly from the name Kaffa, a former kingdom and region in Ethiopia that exported coffee.
caja f. (Noun) "box," "case"

13th cent. From Catalan caixa 'id.' or, less likely, from Occitan caissa 'id.' Both from Latin capsa 'id.,' from capere "to take" (see caber).
caliente (Adjective) "hot"

13th cent. From Latin calentem, accusative of calens 'id.' From calere "to be hot," "to be warm." From Proto-Italic *kalē- 'id.' From Proto-Indo-European *ḱlh1-eh1- 'id.' From a root *ḱel- "warm."

Romance: Western Vulgar Latin: Asturian caliente, Portuguese quente, Galician quente, Catalan calent

Indo-European: Celtic *klito-: Middle Welsh clyd; Germanic *hlēwa-: Old Norse hlár, Old High German lāo; Balto-Slavic *ḱlto-: Lithuanian šil̃tas, Latvian sìlts
callar (Verb) "to silence"

12th cent. From Vulgar Latin *callare "to lower," from Latin calare 'id.,' from Greek χαλᾶν (khalan) 'id.' Of unknown origin.

Romance: Western Vulgar Latin: Asturian callar, Portuguese calar, Galician calar, Catalan callar, Italian calare "to lower"
calma f. (Noun) "calm"

14th cent. Probably from Catalan calma "calm," "calm seas" or Italian calma 'id.,' from Latin cauma "heat of a midday sun," from Ancient Greek καῦμα (kaûma) "heat," from Ancient Greek καίειν (kaíen) "to burn." Mycenaean -ka-wo. According to Beekes (2014), from a pre-form *κάϝω (káwo). From Proto-Indo-European *keh2-u̯- 'id.'

Hellenic: Attic κάω (káo), Mycenaean -ka-wo

The word was originally a nautical term for the heat during midday, and came also to mean the tranquil waters during that time.