stenosis           
noun [ C or U ]  medical specialized uk/stɪˈnəʊ.sɪs/ us/stəˈnoʊ.sɪs/  stenoses
 (身体内通道或孔口)狭窄;变窄
a part of a passage or opening in the body that has become abnormally narrow, or the act of this happening
  血管(或导管)异常收缩(或变窄)
abnormal constriction or narrowing of a blood vessel or duct