gargantuan - huge
‘Gargantuan’ was originally used in association with a large appetite or quantity of food, but is now more typically seen in the context of a herculean effort or task. The term can also be used to describe an exceptionally large person.
It required a gargantuan effort, but we managed to complete the project before the deadline.
In office block architecture in recent years, there has been an increasing trend towards gargantuanism.
I thought the company’s financial targets were gargantuanly optimistic considering our recent difficulties.