absentarse

An obsolete variant of ausentar (to absent oneself, be away) — the RAE itself marks absentarse as desusado (disused). Modern Spanish uses ausentarse in every register, from casual excuses to formal attendance records.

• El texto antiguo dice que el reo se absentó del juicio. — The old text says the defendant absented himself from the trial.
• Los cronistas usaban absentarse donde hoy escribimos ausentarse. — Chroniclers used absentarse where today we write ausentarse.
• El diccionario histórico recoge absentarse como forma en desuso. — The historical dictionary records absentarse as a disused form.

Don't use absentarse in modern writing or speech — it's an obsolete form; ausentarse is the verb every native speaker actually uses and expects.

Often confused with ausentar.