significans
Could not find significantissimo in Logeion dictionaries.
significantissimo Adjective: masculine ablative singular superlative, Adjective: neuter dative singular superlative, Adjective: masculine dative singular superlative, Adjective: neuter ablative singular superlative of significans
signĭfĭcans, antis, Part. and P. a. of significo.
sīgnificāns, antis, PAdi. (significo), I) bezeichnend, treffend, deutlich, verba significantia et nitida, Quint. 11, 1, 2: significantissimum vocabulum, Gell. 1, 15, 17. – II) anschaulich, locorum dilucida et significans descriptio, die Orientierung über Örtlichkeiten, Quint. 9, 2, 44: quia significantius est, Quint. 8, 6, 6.
signĭfĭcāns, tis, ¶ 1 part. de significo ¶ 2 adjt , qui exprime bien, expressif : Quint. 9, 2, 44 ; 11, 1, 2 ; 12, 10, 21 || -tior Quint. 8, 2, 9 ; -tissimus Gell. 1, 15, 17.