Give testimony (5)
'give testimony' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for swear that I've seen before include "Affirm" , "Express annoyance" , "Utter obscenities or take an oath" , "Curse" , "Promise on oath" .)
'give testimony' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for bear witness that I've seen before include "Give testimony" , "Testify (to)" .)