a coined
phrase meaning extremely calm, free from agitation or excitement; undisturbed. This
phrase may be an allusion to the practice of an oyster cementing itself to a
firm surface such as a
rock or
old shell and remaining attached and largely motionless.
very calm. A variation of the
phrase happy as a
clam at
high tide, which comes from the
fact that clams, considered a delicacy in America, are gathered only at low
tide. In other words, a
clam would be happy at
high tide because it would not be being gathered for food. Similarly, oysters withdraw into their shells when the
tide goes down. So, an oyster would be very calm in
high tide.