kinda-ish. like if a kid is late for school and he tells the teacher that he sprained his wrist and had to go to the doctors, he has a legitimate excuse, or alibi. its mostly used in cop shows, where they have a suspect, but the suspect has to give an alibi to explain why he/she was no where near or wasn't able to do the crime
If you say that you were at a certain place, at a certain time, and there were others there, then they are your alibis because they can testify that you were there and at what time. Hope that makes sense.