As far as I'm aware the US does have free OTA TV. A quick google tells me that basic cable means the cheapest tier of cable. So maybe equivalent to a sky/cable entertainment package?

Yep, we do have free OTA television. Basic Cable generally comprises the local free OTA channels plus a number of mostly ad-supported channels.

The basic cable A&E began its life as “Arts & Entertainment” and was originally a mix of British import shows and high culture presentations (e.g., televised orchestra concerts). But much like carcinisation in aquatic invertebrates, for basic cable, apparently channels tend to evolve towards mostly showing Law & Order reruns.