There's more than one way to be sympathetic :)

With 12 of the strings on a sitar having equal (thin) diameter, but different lengths so they can be tuned to the 12 notes in the scale, these are also unplayed strings which contribute to the sound by resonating underneath the main course of strings which are the ones fretted and manually played on.

That's so endearing I guess that's why they call them sympathetic strings ;)

While my guitar gently weeps, etc. . .