'aquiver' originates from the prefix 'a-' (meaning 'on, in a state') combined with the verb 'quiver' (to tremble).

'aquiver' was formed in Early Modern English by adding the prefix 'a-' to the existing verb 'quiver' (Old English root 'cwifer' or related forms meaning 'to tremble'), producing the adjective meaning 'in a trembling state'.

Initially, it meant 'in a trembling or quivering state' and over time has retained that core sense while also being used figuratively for excited or expectant agitation.