smoothbore smoothback • smoothbored · · · Info · Definitions · Synonyms · Characters · · smoothbore · · Text Latin · · Script 10 · · Length Definitions · · · (noun) a firearm that has no rifling. · · Noun Definition 1 (adj) of a firearm; not having rifling or internal spiral grooves inside the barrel. Synonyms: unrifled (vs. rifled). · · Adjective Definition 1 Synonyms · · · unrifled · · Synonym 1 Characters · · b latin small letter b U+0062 e latin small letter e U+0065 h latin small letter h U+0068 m latin small letter m U+006D o latin small letter o U+006F r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074