Indices are indexes, so the singular would be index.
The possessive singular of all English nouns is formed by adding -'s: index's.
Index
The possessive form is Amos's.
The singular possessive form is herd's.
The singular possessive form is heart's; the plural possessive form is hearts'.
The singular possessive form is grotto's.
The singular possessive form is lesson's.
The possessive form of "index" is "index's." For example, "the index's values are displayed in alphabetical order."
The possessive form is Amos's.
The singular form is goose; the singular possessive form is goose's.The plural form is geese; the plural possessive form is geese's.
Quantum is singular, not singular possessive. The singular possessive form is quantum's.
The singular possessive form is week's.
The singular possessive form is contralto's.
The singular possessive form is aircraft's.
The singular possessive form is frontiersman's.
The singular possessive form is speculum's.
"index" is the singular form - "indices" is the plural :)
The singular possessive form is herd's.
The singular possessive form is heart's; the plural possessive form is hearts'.