How to tag this type of lighting?

[Wild_Spike]

How do you tag these types of lights?

[Casey_boy]

I would call that either a post light or bollard light (e.g. [1]).

As for tagging, highway=street_lamp seems to be the only documented way. The tag lamp_mount=bollard has been used 12 times in conjunction with street lamp.

You can also combine with lamp_type=* (probably LED).

[SK53]

I’d suggest height=* too. There are lots on my local university campus which are about 95 cm.