For other uses of the word silver see here
Silver is an inhabitant of the planet Shand, and is a sociologist, comparative historian, linguist and animal meat herder (the Shandi being firm believers in multiskilling). About three metres high and looking like a cross between a bear and a walrus, it is for her linguistic abilities that Jago Jalo hires her on their trip to the Discworld. Silver is able to remove her Shand tusks to be able to converse better in alien languages which require more precise use of sibilants. Tusks are a status symbol for adult Shand: having had hers replaced by artificial ones that she can unscrew at need (or she would otherwise have a serious Igor-like lisp) is a major sacrifice proving how dedicated she is to her profession as linguist and diplomat.
Shandi can only survive for about two days without food before turning into ravenous beasts, so when their food replicator is destroyed it gives Kin and Marco a lot of motivation to find a replacement quickly. Like all Strata characters, Silver only appears in this one book.