in company with

accordingly collectively cooperatively in tandem mutually simultaneously together unitedly

conjointly

agreeably alike arm in arm coincidentally combined companionably concomitantly concurrently connectedly en masse hand in glove hand in hand harmoniously in a group in common in concert in conjunction in league in partnership in unison inextricably inseparably intimately reciprocally side by side similarly synchronically with one another

singly

along the side of apace with at the side of beside by by the side of close at hand close-by equal with next to parallel to side by side

away