Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ex-signo (exign-), āvi, ātum, 1, v. a., to write out, note down, record (very rare): omnia istaec quae tu dixti, scio, vel exsignavero, I could write it down exactly, Plaut. Trin. 3, 2, 29: pontifici sacra omnia exscripta exsignataque attribuit, Liv. 1, 20, 5.