Gigantic, a.
Etymology: [L. gigas, -antis, giant. See Giant.]
1. Of extraordinary size; like a giant.
2. Such as a giant might use, make, or cause; immense; tremendous; extraordinarly; as, gigantic deeds; gigantic wickedness. Milton. When descends on the Atlantic The gigantic Strom wind of the equinox. Longfellow.
Shades of meaning
Fernald has no entry of its own for gigantic; he lists it under large.
He lists it without comment; the entries above explain its neighbors.