胎たい齢れいMeanings1nounembryonic age; fetal ageMedical term used in obstetrics and embryology to describe the age of an embryo or fetus, typically measured from fertilization.超ちょう音おん波ぱ検けん査さで胎たい齢れいを推すい定ていする。Estimate the fetal age with an ultrasound examination.