Gargantuan (?.)

• Atlantean
• Brobdingnagian
• Cyclopean
• Herculean
• Homeric
• abysmal
• amplitudinous
• astronomic
• astronomical
• awesome
• boundless
• bulky
• colossal
• cosmic
• elephantine
• enormous
• epic
• extensive
• galactic
• giant
• giantlike
• gigantic
• heroic
• huge
• immeasurable
• immense
• infinite
• jumbo
• king-size
• large
• mammoth
• massive
• massy
• mighty
• monster
• monstrous
• monumental
• mountainous
• outsize
• overgrown
• prodigious
• profound
• sizable
• spacious
• stupendous
• titanic
• towering
• tremendous
• vast
• voluminous
• weighty