n.
Function: noun
Usage: often attrib
Etymology: 1 clam; from the clamping action of the shells
Date: circa 1520
1 a : any of numerous edible marine bivalve mollusks living in sand or mud b : a freshwater mussel
2 : a stolid or closemouthed person
3 : CLAMSHELL
4 : DOLLAR 3
clam[2]