"operator" - key terms from Wikipedia

airport operator
assignment operator
boom operator
bounded operator
bridge operator
cable tv operator
camera operator
comparison operator
differential operator
donor operator
former operator
harris operator
irc operator
ladder operator
laplace operator
largest operator
linear operator
machine operator
market operator
mobile operator
mobile phone operator
modal operator
network operator
normal operator
npg operator
operator
operator	interface
operator	mutants
operator	network
operator	overloading
operator	status
operator	that originates the call
operator	would
public transport operator
radar operator
radio operator
ranger operator	series
relay operator
smooth operator
sobel operator
special operator
standard query operator
system operator
telephone operator
ternary operator
tour operator
unbounded operator
unitary operator
wimax operator
wireless operator