largus.

Unknown. Often connected with Proto-Indo-European *leh₂y- (“lard, fat, grease”) (see lārdum, lāridum (“bacon”) and laetus (“fat, happy”)), via Proto-Italic *lajes-ago-, though De Vaan finds this problematic and doubts that the long vowel is original. Compare also Ancient Greek λᾱρῑνός (lārīnós, “fattened; fatty”), with -r- as in Latin perhaps coming from Proto-Indo-European *leh₂-r-; this could further be a different suffixed form of the same Proto-Indo-European *leh₂- (“to fatten; fat”) whence *leh₂-y-, notwithstanding some phonetic and morphological difficulties. These roots are however disputed and more likely reflect Mediterranean substrate words or Wanderwörter, while Latin lāridum is thought to be a borrowing from Ancient Greek. Also may be connected to lascīvus, from Proto-Indo-European *las- (“to be willing, covetous”), if such a root exists, but the semantics are suspicious as well as the *a. Prósper, presuming a sound law in which *d became *l before *a, derives largus from Proto-Indo-European *dl̥h₁gʰós via a sequence of either *dlāɣos > *dālɣos (with metathesis) > *lālɣos > *lalgos > largus (with dissimilation), or alternatively *dalaɣos > *lalaɣos > *lalɣos (with syncope) > *lalgos > largus. (Note that these lambdacisms can alternatively be viewed as assimilation to the internal *l even if the sound law is not accepted.)