the practice of using le as a direct object pronoun when referring to people
“Se denomina leísmo al fenómeno que consiste en utilizar los pronombres típicos de complemento indirecto (le, les), que solo reflejan el número del sustantivo al que sustituyen, en lugar de los propios del complemento directo, que reflejan el número y el género (lo, los, la, las).” — The phenomenon that we call leísmo consists of using the typical indirect object pronouns (le, les), which only reflect the number of the noun it replaces, in place of the proper direct object pronouns, which reflect number and gender (lo, los, la, las).
Related: leísmo de cortesía
Etymology tree Spanish le Proto-Indo-European *-id- Proto-Indo-European *-yéti Proto-Indo-European *-idyéti Proto-Hellenic *-íďďō Ancient Greek -ῐ́ζω (-ĭ́zō) Proto-Indo-European *-mos Proto-Indo-European *-mós Ancient Greek -μός (-mós) Ancient Greek -ῐσμός (-ĭsmós)der. Latin -ismusbor. Spanish -ismo Spanish leísmo From le + -ismo.