The only free and comprehensive online etymological dictionary of the Spanish language
larga f. (Noun) "dilation;" "pool cue;" "instrument to lengthen shoes"

All feminized nominal derivations of the adjective largo.

Also the origin of the surnames Largo, Larga, Largacha and Largoza.
largar (Verb) "to release;" "to slacken"

15th cent. From largo.
largo (Adjective) "long"

12th cent. From Latin largus 'id.' Of unknown origin.

Romance: Western Vulgar Latin: Asturian llargu, Portuguese largo, Galician largo, Catalan llarg, French large, Italian largo; Eastern Vulgar Latin: Aromanian largu, Romanian larg; Sardinian: lalgu
lástima f. (Noun) "pity"

16th cent. From Vulgar Latin *blastema "lament," "hurt," but originally "blasphemy;" from *blastemare "to blaspheme" (see lastimar).
lastimar (Verb) "to hurt"

Late 15th cent. From Vulgar Latin *blastemare "to injure," but originally "to blaspheme." The sense evolution is from a blasphemy to a curse; later a curse intended to harm, then to the harm itself. From Latin blasphemare "to blaspheme." The word was re-introduced in Spanish as blasfemar.

Romance: Western Vulgar Latin: Portuguese lastimar, Galician , Catalan blasmar, French blâmer, Italian bestemmiare ; Eastern Vulgar Latin: Aromanian blastim, Romanian blestema ; Sardinian: fraltimare
le (Pronoun) "(to) him/her"

From Latin illi "to him," "to her," "to it;" dative of ille "that (person)" (see él).
leche f. (Noun) "milk"

12th cent. From Latin lactem, accusative of lac 'id.' From Proto-Italic *glagt- 'id.' From Proto-Indo-European *gl̥gt 'id.' Probably borrowed from another language.

Romance: Western Vulgar Latin: Asturian lleche, Portuguese leite, Galician leite, Catalan llet, French lait, Italian latte; Eastern Vulgar Latin: Aromanian lapti, Romanian lapte; Sardinian: late

Indo-European: Hellenic: Ancient Greek γάλα (gála) "milk," γάλακτος (gálaktos) 'id.;' Armenian: kaxc' "milk"
lecho m. (Noun) "bed"

11th cent. Old Spanish leito. Now largely replaced by cama. From Latin lectus 'id.' From Proto-Italic *lekto- 'id.,' a formation from the verb *leχ-e/o- "to lie down." From Proto-Indo-European *legh-e/o- 'id.'

Romance: Western Vulgar Latin: Portuguese leito, Catalan llit, French lit, Italian letto ; Sardinian: letu
leer (Verb) "to read"

12th cent. From Latin legere "to read," "to gather." From Proto-Italic *leg-e/o- "to gather." From Proto-Indo-European *leǵ-e/o- 'id.'

Romance: Western Vulgar Latin: Asturian lleer, Portuguese ler, Galician ler, Catalan llegir, French lire, Italian leggere; Sardinian: lègere

Italic: Paelignian lexe "you read," Marrucinian leexe 'id.'

Indo-European: Albanian: mb-ledh "to collect;" Hellenic: Ancient Greek λέγειν (légein) "to reckon"
legra f. (Noun) (med.) "rounded scalpel"

13th cent. Probably from Latin ligula "spoon" (see lígula).

Romance: Western Vulgar Latin: Italian lingula; Eastern Vulgar Latin: Aromanian lingurã, Romanian lingură