Over in Australia, "social security" is merely the technical name for all of the government welfare programs handled by the Department of Human Services, including Age Pension, Youth Allowance (study benefits), Newstart Allowance (unemployment benefits), Disability Support Pension and so on and so forth. No-one really uses the term "social security" unless you're reading the legislation. With no further qualification, "the pension" means the Age Pension.

What we call "super" you'd call KiwiSaver, except over here it's mandatory. I suspect the NZ use of the term "superannuation" is probably closer to the original/traditional use of the term.