testigo
/tesˈtiɡo/ · A2 · noun · mf
witness
testigo = one who testifies: same Latin root as testify and testimony
From Old Spanish testiguar, from Latin testificare (to bear witness), built on testis (witness). English testify, testimony and attest share the root. The -igo ending is the worn-down -ificare. Same form for both genders: el testigo, la testigo.