-ed Look up -ed at Dictionary.com
past participle suffix of weak verbs, from Old English -ed, -ad, -od (leveled to -ed in Middle English), from Proto-Germanic *-do- (cognates: Old High German -ta, German -t, Old Norse -þa, Gothic -da, -þs), from PIE *-to- (cognates: Sanskrit -tah, Greek -tos, Latin -tus; see -th (1)).

Originally fully pronounced, as still in beloved (which, with blessed, accursed, and a few others retains the full pronunciation through liturgical readings). In 16c.-18c. often written -t when so pronounced (usually after a consonant or short vowel), and still so where a long vowel in the stem is short in the past participle (as in crept, slept, etc.). In some older words both forms exist, with different shades of meaning, as in gilded/gilt, burned/burnt.