The 31-year-old, last seen with the Washington Redskins, has not played 16 games in a season since 2010.
With the signing, though, Giants general manager Jerry Reese is hoping to strike gold for a second time on the injured-but-talented aging star market.
Reese traded a seventh-round pick for Jon Beason two years ago and watched as the All-Pro transformed a struggling defense.
Though Meriweather's impact may be a little more understated, the team had no other options. So far this camp, they are down seven members of the secondary.