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Perfect passive participle of asserō (“declare free; claim as a slave; protect; arrogate; maintain, assert”).

assertus (feminine asserta, neuter assertum); first/second-declension participle

1. declared free, set free, liberated, having been liberated
2. claimed as a slave, having been claimed as a slave
3. protected, preserved, defended, having been protected
4. arrogated, claimed by oneself, having been arrogated
5. maintained, affirmed, alleged, asserted, declared, having been asserted

First/second-declension adjective.

• “assertus”, in Charlton T. Lewis and Charles Short (1879), A Latin Dictionary, Oxford: Clarendon Press
• “assertus”, in Gaffiot, Félix (1934), Dictionnaire illustré latin-français, Hachette.