WoTD: brobdingnagian

Definition:
1. Of extraordinary size; gigantic; enormous.

Webber's eyes boggled, his hands flapped. "It's... it's..."
"It's what?" O'Toole smoothed the paper, set the fountain pen on the desk, the ink still drying. He stood. "What's out there?"
"I've never seen such a thing. It's girth is inconcievable. The breadth and height are such I've never witnessed in my entire life. It's gigantic, massive, stupendously ginormous."
"What on earth are you talking about?" O'Toole moved around the desk, walked to the window. Drawing the curtain aside, he looked out. The sight rocked him backwards and his mind blanked.
"It's brobdingnagian," Weber said, awestruck.
"Yes," O'Toole managed after a long moment. "Yes, it is."

I'll let you decide what it is the two men saw.