Windbag
Windbag was an insulting term to describe a person who talked too much.

In 2374, Kathryn Janeway described Vice Admiral  as "a bit of a windbag". Later, upon retrieving another portion of the transmission, Seven of Nine suggested it might be an addendum from Hayes, adding, "You did designate him a windbag." ()

See also 
 Blatherskite

Insults