parameter
/pəˈræmɪtə(r); pə`ræmətɚ/ n
1 (mathematics数) quantity that does not vary in a particular case but does vary in other cases 参量; 参数.
2 characteristic or feature, esp one that can be measured or quantified 特点, 特性（尤指可以衡量或计量的）.
3 (usu pl 通常作复数) limiting factor or characteristic; limit （限定性的）因素, 特性; 界限
We have to work within the parameters of time and budget. 我们工作受时间和财力所限.