thereto

adverb2

1. •
   (formal) To that.

   • 'There,' she went on, 'it [a scarab] must be one like it, and yet never did I see one like it, for thereto hung a history, and he who wore it prized it much.['] — 1886
2. •
   (literary, no longer used) To it.

   • He strung the angelot; / Made rhymes thereto; […] — 1840