efficacissimo

== Italian == === Etymology === From efficace +‎ -issimo. === Pronunciation === IPA(key): /ef.fi.kaˈt͡ʃis.si.mo/ Rhymes: -issimo Hyphenation: ef‧fi‧ca‧cìs‧si‧mo === Adjective === efficacissimo (feminine efficacissima, masculine plural efficacissimi, feminine plural efficacissime) superlative degree of efficace (“very effective”)