It is a rare case found in certain dialects of Baltic-Finnic languages.
[1][2] In the general pattern of the loss of a final vowel when compared to Finnish, the Estonian exessive ending is -nt.
It appears in words such as kodunt 'away from home' and tagant 'from behind', or South Estonian mant 'away from the vicinity of something'.
The exessive is more common in the language of Estonian folk songs.
There are some word forms in Finnish dialects in which the exessive appears in a locative sense.