Adjective
The word is derived from gassy
Hughes (2004), 402 Leocadia Weiss (née Zorrilla, b. 1790) Junquera, 13 Stevenson, 243 the artist's maid, younger by 35 years, and a distant relative, Gassier, 103 lived with and cared for Goya after Bayeu's death. Source: Internet