If that counts, I’m throwing in Donald Sutherand’s wordless shriek at the end of the '70s Invasion of the Body Snatchers.
“Vienna” - Jean Reno,* Ronin*
Works for me. Us '70s minimal-dialogue appreciationists have to stick together.
Zero Mostel’s maniacal grin in A Funny Thing Happened on the Way to the Forum.
This was always my favorite. Same word, Andy Warhols Trash
Check 1:12:35
“Whoa” - Keanu Reeves, pick a movie.
"Reeeeeeeeeeee-VENGE!!!" - A Fish Called Wanda
“FREEEEDOM!!!” - Braveheart
“Sussudio” - American Psycho
“Hieneken” - Blue Velvet
Isabelle Huppert, correcting the French pronunciation of “le force” in “I 
Huckabees”. Completely thrown away, but screaming unintended sexuality.
“Homo…sexuality” Heavanly Creatures
“if you don’t listen…then to hell with you” -Conan
“Don’t choke on your aspirations” -darth Vader
“Multipass” – Leeloo (Mila Jovivich) in “The Fifth Element”
Toga! Toga! Toga!; hey, it’s one word.
“Shocking” – James Bond after tossing an electric heater into the bathtub to electrocute hia assailant.
Great quotes, but we’ll have to keep it to the OP’s “one word” criterion.
Those “looks” referred to in earlier posts (re: Sutherland, Balsam) - I 'spose I’ll give that a pass.
“Redrum” - The Shining
ok, a stretch…Dr. Evil going all “SH!” on Scott
In the looks dept: buddy eyeing gun on the street while Clint is pointing one at him.
In The Shining - two great looks bits - a GREAT shot of Jack just simply staring out the window, in the early stages of his deterioration. No dialogue or action, just a swelling, nasty score as the camera slowly zooms in on him, and he’s just standing there, looking all, well, you get the idea.
And later when he’s sitting down at the bar, he brings he hands away from his fatigued face, which undergoes a brilliant transformation into an effusive mug of a smile at seeing the still unseen Floyd, the bartender.
Ok, if we’re doing looks, and The Shining, then I have to submit the look of stunned horror on Danny’s face when he is playing darts and turns around and sees the creepy sisters for the first time.
“Groovy.” - Army of Darkness
One of my favorite scenes in"A Christmas Story":
Ralphie: “FFFuuuudge!”
Narator: “Except, I didn’t really say fudge.”