Relatively large in scale, size, extent, number (i.e. having many parts or members) or duration (i.e. relatively long); very big.
A great storm is approaching our shores.
2
Of larger size or more importance than others of its kind.
the great auk
3
(qualifying nouns of family relationship) Involving more generations than the qualified word implies — as many extra generations as repetitions of the word great (from 1510s). [see Derived terms]