Gasohol is the word formed using all the letters in goolash.
gaininggallonsgambledgardensgarmentgetawaygatewaygathersgeneralgentilegesturegettingghastlygiraffegirlishglassesglimmerglistenglorifygolfinggoslingglowinggradinggrantedglaringgleefulgloatedgovernsgravitygreatlygrowinggravelygrantedgreetedgravinggriffingrimacegrizzlygrosslygroomedgroomergroovedgrufflygrumblegruntedguessedgunshotguzzledgushinggutting
gaininggallonsgambledgardensgarmentgetawaygatewaygathersgeneralgentilegesturegettingghastlygiraffegirlishglassesglimmerglistenglorifygolfinggoslingglowinggradinggrantedglaringgleefulgloatedgovernsgravitygreatlygrowinggravelygrantedgreetedgravinggriffingrimacegrizzlygrosslygroomedgroomergroovedgrufflygrumblegruntedguessedgunshotguzzledgushinggutting
juggler
Blogger is a seven letter word that the 3rd letter is an O and the 4th letter is a G.
dogging
highway
getaway
Growing is first one I thought of
felopog
Blowing
grapple
No eight letter words match that description. However, a seven letter word, basking, and a six letter word, asking, contain a portion of those letters.