What is this inductor symbol from a video circuit?
Note how it says "330ns", a proper inductor would have a value in Henries.

My guess is that this is an Analog delay line like this:



Note how it has 3 connections of which one is ground which is connected to the tube and the shield.

I actually came across one of these many many years ago, probably in some video equipment I scrapped for parts. At the time didn't realize it was a delay line. 

The "330 ns" and a search for "delay line" led me to the Wikipedia page. The delay line in the picture has 450 ns delay so 330 ns looks like that could be achieved with a similar component.

Sidenote:
there are also Piezo electrical delay lines (see an example here) used in analog video equipment and I have seen lots of these and most have a 64us delay time which relates to the old PAL television standard (64 us is one horizontal line of the image). But 64 us is much larger than 330 ns so I knew that these were different types.