neonatal period neonatal mortality rate • neonate · · · Info · Definitions · Characters · · neonatal period · · Text Common · · Latin · · Scripts 15 · · Length 6 · · Syllables Definitions · · · (noun) the first 28 days of life. Synonyms: neonatal period. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 d latin small letter d U+0064 e latin small letter e U+0065 i latin small letter i U+0069 l latin small letter l U+006C n latin small letter n U+006E o latin small letter o U+006F p latin small letter p U+0070 r latin small letter r U+0072 t latin small letter t U+0074