What is "lettic"

Lettic \Let"tic\ (l[e^]t"t[i^]k), a.

1. Of or pertaining to the Letts; Lettish.

2. Of or pertaining to a branch of the Slavic family, subdivided into Lettish, Lithuanian, and Old Prussian. -- n.

   1. The language of the Letts; Lettish.

   2. The language of the Lettic race, including Lettish, Lithuanian, and Old Prussian.