Difference between Shut Up and Clam Up

SHUT UP vs CLAM UP: ADJECTIVE

I don't believe it!, no way!
Of a person, to stop talking or (of a person or thing) making noise.
To put (an object) in a secure enclosed place.
To enclose (a person, animal or thing) in a room or other place so that it cannot leave.
To terminate (a business).
To close (a building) so that no one can enter.
Place in a place where something cannot be removed or someone cannot escape
Cause to be quiet or not talk
Refuse to talk or stop talking; fall silent

Button up, Belt up, Dummy up, Lock away, Hush up, Still, Lock, Hush, Silence, Quieten, Put away, Close up, Lock in, Lock up, Be quiet

Whisperingly, Blurt out, Make noise, Silentiary, Silence, Quiet down, Silent, Pipe down, Close up, Belt up, Button up, Keep mum, Dummy up, Shut up, Be quiet

Confined, Lock away, Hush up, Dummy up, Clam up, Button up, Belt up, Still, Lock, Hush, Silence, Quieten, Close up, Lock in, Lock up

Rattle off, Shout down, Taciturnly, Whisperingly, Blurt out, Make noise, Silentiary, Silence, Quiet down, Silent, Pipe down, Close up, Dummy up, Button up, Belt up

They must either put up or shut up.
His favorite sayings, back up, drop it, shut up.
Russia tells BRD, US, put up or shut up.
You told me to put up or shut up.
She shelf boston put up or shut up reficar.
The three marks of a good preachers are these: He stands up, speaks up, and knows when to shut up!
Saudi Arabia is a totalitarian state where my daughters are locked up, wrapped up and shut up.
Shut up, shut up, and take everything, disembodied code voice, take everything!
Poor women in psychological research: Shut up and shut out.
Shut up, dammit, all of you just shut UP!

Children usually forget about the recorder, though its presence may affect some either to put on a performance or to clam up.
When he saw them clam up he knew if he released it that would be come the story.
There were certain quiet moments in which Raven would start to speak, then clam up again, or hesitate and change the subject.
There is always a temptation to clam up at a time like this.
But victims often tend to clam up and may not talk to you.
Blood Girl: Yeah, when I get nervous I sort of clam up.
They, in turn, clam up and refuse to engage in anything productive.
The instant you do, the prospect will clam up.
When the oyster is out of balance, they can be reluctant, withdrawn, and may clam up.
Of course, there can be times when it is appropriate to clam up and stop cooperating.