1. (noun) (astronomy) a hypothetical huge collection of comets orbiting the sun far beyond the orbit of Pluto; perturbations (as by other stars) can upset a comet's orbit and may send it tumbling toward the sun

• accumulation
• aggregation
• assemblage
• collection

1. (noun) (astronomy) a hypothetical huge collection of comets orbiting the sun far beyond the orbit of Pluto; perturbations (as by other stars) can upset a comet's orbit and may send it tumbling toward the sun

• astronomy
• uranology