freeze up
phr. v..phr. v.. to suddenly stop moving or speaking because you are nervous or scared. It can also mean a computer or machine stops working and stays still.
phr. v.. to become suddenly incapable of action or expression due to psychological pressure; also used technically to describe a system or software becoming unresponsive.
I always freeze up when I have to speak in public.
The actor was doing great until he saw the famous director in the audience and completely froze up.
The application tends to freeze up whenever the user attempts to render high-resolution video files without sufficient memory.
usually used without an object to describe a person's reaction or a machine's failure.
contrast with 'lock up' for machines or 'panic' for people; 'freeze up' specifically emphasizes the lack of movement or the inability to continue a process.
The computer was frozen up by the virus.The computer froze up because of the virus.while 'frozen' is the participle, 'freeze up' is most commonly used as an intransitive verb describing the subject's own state.