Blat \Blat\, v. i. To cry, as a calf or sheep; to bleat; to make a senseless noise; to talk inconsiderately. [Low]
Source: Webster's Revised Unabridged Dictionary (1913)
Blat \Blat\, v. t. To utter inconsiderately. [Low]
If I have anything on my mind, I have to blat it right out. --W. D. Howells.