This is the verse translation, not a definition of the individual word.
O you who believe, when death approaches one of you, call upon two just Muslim men as witnesses when you make a bequest, or two non-Muslims if you are afflicted with death while you are traveling. But if you have some doubt, keep them both after prayer[1] and let them swear by Allah, “We will not trade our testimony for any price, even in favor of a close relative, nor will we conceal the testimony enjoined by Allah, for then we would surely be among the sinners.”
Source
[1] Prayers are usually attended by a congregation of people.