"principal" - key terms from Wikipedia

assistant principal
current principal
elementary principal
elementary school principal
first principal	component
garter principal	king of arms
notional principal	amount
principal
principal	and the pauper
principal	axes
principal	axis
principal	balance
principal	branch
principal	bundle
principal	cast
principal	chief
principal	cities
principal	component
principal	component analysis
principal	conductor
principal	cornet
principal	curvature
principal	dancer
principal	deity
principal	deputy
principal	directions
principal	euphonium
principal	financial group
principal	ideal
principal	ideal domain
principal	ideal ring
principal	james
principal	meridian
principal	note
principal	part
principal	parts
principal	photography
principal	quantum number
principal	reception room
principal	residence
principal	skinner
principal	square root
principal	stresses
principal	term
principal	value
principal	victoria
school principal
team principal
vice principal
victoria principal