二に分ぶん脊せき椎つい症しょうにぶんせきついしょうMeanings1nounspina bifidamedicineMedical term for a congenital neural tube defect where the spinal column does not close completely.二に分ぶん脊せき椎つい症しょうは、胎たい児じ期きに神しん経けい管かんが正せい常じょうに閉とじないことで起おこります。Spina bifida occurs when the neural tube does not close properly during fetal development.