Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dis-perdo, dĭdi, dĭtum, 3, v. a., to destroy, spoil, ruin (rare but class.): bibe, es, disperde rem, Plaut. Cas. 2, 3, 32; cf. id. Trin. 2, 2, 58: ut a majoribus nostris possessiones relictas disperdat et dissipet, * Cic. Agr. 1, 1, 2: imaginem, Gell. 15, 31, 4.
Poet.: stridenti miserum stipula disperdere carmen, to spoil, * Verg. E. 3, 27.
Of personal objects: lenonem, Plaut. Poen. 4, 2, 96: qui tot cives Romanos occidit, arripuit, disperdidit, Vatin. ap. Cic. Fam. 5, 10: inimicos, Vulg. Psa. 142, 11 et saep.
(The pass. forms are not found, dispereo taking their place. In Lucr. 2, 831, dispergitur is the true reading.)