I've heard this expression (I think it was two words) long time ago. The expression meaning is that
there is a protection/preventative measure against access/use by those who do not understand or know the subject. To me [as non-native speaker] the meaning was immediately clear when I've heard it, but now I cannot recall this expression.
I've heard it being used in software development industry, in casual speech only (would not be suitable for official communications). But I imagine it can be used in other situations where the same meaning applies.
It is similar to "fail-safe" but with the stress on the fact that "fail" would come from someone who does not know what they are doing. Which can be diminishing or even insulting towards end user (and so why not suitable for official communications).
As this is better suited for casual communication, the usage could appear as:
"Let's put a _______________ there to make sure this does not happen" or
"Let's make it _______ to avoid that in the future" (as that is how perhaps software developers would communicate such case to each other ;)