Latin word pactum comes from Proto-Indo-European *peh₂ǵ-, Proto-Indo-European *paḱ-, and later Latin pax (Silence! be silent! hush! Harmony. Peace.)
*peh₂ǵ- (Proto-Indo-European)
*paḱ- (Proto-Indo-European)
pax (Latin)
Silence! be silent! hush! Harmony. Peace.
pacare (Latin)
paciscor (Latin)
I make a bargain, contract or agreement with.
pactum (Latin)
Agreement, bargain. Pact.