Impede comes from Latin impedīre, literally 'to thrust the feet into shackles,' from locative in- (into) + pēs (foot), PIE *ped-. Its perfect antonym is expedite (free the feet). Together they preserve a Roman military metaphor of soldiers either shackled by baggage or freed for rapid march.
To obstruct, hinder, or delay the progress or movement of someone or something.
From Latin 'impedīre' (to entangle the feet, to hinder, to obstruct), from 'in-' (in, into) + 'pēs' / 'pedis' (foot), from Proto-Indo-European *pṓds / *ped- (foot). The literal image is of something caught in the feet — fettered or ensnared at the ankles — a metaphor vivid enough to survive intact into English. The PIE root *ped- is extraordinarily productive: it yielded Greek 'pous/podos' (foot, source of 'podium,' 'octopus,' and 'antipode'), Latin 'pēs/pedis' (foot, source of 'pedal,' 'pedestrian,' 'centipede,' and 'expedite' — literally to free
Impede and expedite form one of the most elegant antonym pairs in English: both built on Latin pēs (foot), but impede = shackle the feet (in- 'into') while expedite = free them (ex- 'out of'). Caesar exploited this contrast in De Bello Gallico, distinguishing impedītī (burdened soldiers) from expedītī (light troops). The military term impedimenta (baggage train) survives in English as a slightly humorous word for cumbersome luggage.