"invariant" - key terms from Wikipedia

algebraic invariant
class invariant
diffeomorphism invariant
gauge invariant
invariant
invariant	human
invariant	mass
invariant	mod
invariant	sections
invariant	theory
invariant	to rotations
invariant	under
knot invariant
left invariant	vector fields
no invariant	sections
scale invariant
topological invariant
translation invariant