asegurarse

infinitive of asegurar combined with se

(transitive) to secure (to make fast; to close or confine effectually)
(transitive) to assure (to give (someone) confidence in the trustworthiness of)
to claim, to maintain
(transitive) to ensure, to guarantee (to make a pledge to someone)
(reflexive) to make sure, to ensure (to take care that something happens)
(transitive) to insure (to provide for compensation if some specified risk occurs)
to belay