In an astatic manner; without achieving or maintaining a fixed position or equilibrium.
The adverb form of 'astatic' created by adding '-ly.' Standard English word formation for converting adjectives to adverbs.
This is the kind of word that probably sounds more complicated than it is—it just means 'in an unstable way,' but saying it took scientists building a whole prefix structure first.
Complete word intelligence in one call. Free tier — 50 lookups/day.