Accretion

Akkretion

(formation of celestial bodies by the aggregating of matter drawn together by gravity; growth of a celestial body through this process)

Anwachsen

((gradual) increase by an external addition of matter; an instance of this)

Zunahme

(increase by natural growth, especially the gradual increase of organic bodies by the internal addition of matter; amount of such growth)

Zuwachs

((gradual) increase by an external addition of matter; an instance of this)