Geometry.
Gannet
Goul ? :)
gateau
Doing
being
gaininggallonsgambledgardensgarmentgetawaygatewaygathersgeneralgentilegesturegettingghastlygiraffegirlishglassesglimmerglistenglorifygolfinggoslingglowinggradinggrantedglaringgleefulgloatedgovernsgravitygreatlygrowinggravelygrantedgreetedgravinggriffingrimacegrizzlygrosslygroomedgroomergroovedgrufflygrumblegruntedguessedgunshotguzzledgushinggutting
Gondola is a type of boat. It begins with the letter g.
Gannet
grebe
glory
Goul ? :)
GOD
Gash
Growing is first one I thought of
Golgotha, gardenia
growing
Get gnu gun, guy!