first trimester first-told • first vatican council · · · Info · Definitions · Characters · · first trimester · · Text Common · · Latin · · Scripts 15 · · Length 4 · · Syllables Definitions · · · (noun) time period extending from the first day of the last menstrual period through 12 weeks of gestation. Synonyms: first trimester. · · Noun Definition 1 Characters · · space U+0020 e latin small letter e U+0065 f latin small letter f U+0066 i latin small letter i U+0069 m latin small letter m U+006D r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074