invariable
/ɪnˈveərɪəbl/adjective
1- never changing永远不变的, 始终如一的, 恒定的：
disillusion was the almost invariable result.
幻想破灭是几乎固定不变的结局。
1.1
- (of a noun in an inflected language) having the same form in both the singular and the plural, as does relais in French（屈折变化语言的名词）单复数同形的（如法语中relais）
1.2
- Mathematics (of a quantity) constant【数】（数量） 不变的。
派生词
invariability
nouninvariableness
noun词源
late Middle English: from French， or from late Latin invariabilis, from in- 'not' + variabilis （see VARIABLE）.