In a way that affects, involves, or concerns both sides equally.
From the adjective 'bilateral' (from Latin 'bi-' meaning two, and 'lateralis' meaning of the side) plus the adverbial suffix '-ly', which transforms adjectives into adverbs.
Scientists use this word constantly when describing how your brain processes information bilaterally—your left and right hemispheres work together on nearly everything you do, from moving your hands to understanding language.
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