Morgan: You don't understand he is a fragile little gelding, you know still trying to find his legs the real world will crush him.
Ellie: Do you know what a gelding is?
Morgan: (Long pause) It's the... that weird creature from The Dark Crystal. (Impersonates a character from the film) "Smells like Gelding" that... that guy.
Morgan calls Chuck a gelding when what he in fact means is a Gelfling an elf-like creature from Jim Henson's 1982 puppet fantasy film The Dark Cystal. A gelding is a castrated domesticated animal especially a horse.