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dejar (Verb) "to leave"
12th cent. Old Spanish lexar 'id.' In all probability, lexar represents a learned form from Latin laxare, whereas dejar comes from Vulgar Latin *daksare 'id.' (see Penny 2002; cf. Dictionnaire Étymologique Roman). From Latin laxare "to relax" with the l- replaced with d- under influence from Oscan. From the noun laxus (see laja).
Asturian dexar, Portuguese deixar, Galician deixar, Catalan deixar, French laisser, Italian lasciare, Aromanian lãsari, Romanian lăsare, Sardinian lassare

Roberts' (2014) theory that dejar replaced l- with d- under influence from dar fails to explain the many d-initial reflexes in Romance languages that point to a reconstructible etymon in Vulgar Latin.