Rear hub play

[spinelll]

I had my car on jack stands this weekend and as a matter of course, jiggled the rear wheels. I noticed a bit of in-and-out play on the passenger side rear. Not sure if I can measure it. It definitely ain't the lug nuts.
About a year ago I checked and re-torqued those nuts to 100lbs.

Is that play a bearing issue or something other?

Thanks
Leo