Huge thanks, your explanatory skills are impressive indeed. I went online only now after several days of intensive brainwork I tried to go through on my own and was only astonished that we share the similar understanding.
I think I may nailed the essence of my problem of why I was unable to filter out unneeded entries. After failing numerous tests trying to search just for the entries I wanted to be skipped instead of trying to actually I stumbled upon the fact that I had missed the logic when using

Code:

'.*(Safari|[Oo]pera).*

in that it output no results when I tried to feed it as an argument to

Code:

-and -not -path

parameter in the combination with

Code:

'.*(keyword|KEYWORD).*

. I bypassed an obvious thing which was that 1) expressions of the type

Code:

'.*(Safari|[Oo]pera).*

can NOT be arguments to

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-path

,

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-name

and 2) nor it coexist with any other parameters than

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-regex

because it was what the name of the parameter's implies - "a regular extension of the Extended Set" - it could NOT be used to do what I sought not in conjunction with it.
So the correct logic of this part of the command line was

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-regex  '.*(keyword|KEYWORD).* -and -not -regex '.*(Safari|[Oo]pera).*

. Use of -path and -regex on the same line with Extended Set regexes was like comparing incomparable. By further investigation I discovered that I could not make much of use of

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-exec grep

or pipe into either

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-grep

or

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-xargs

, cause grepping is useful mostly for manipulating strings in target files or in output of such commands as

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ls

so I dropped that option.

I looked closely at description of

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-prune

once more and it was this phrase that caught my attention and made into my enlightenment: .

So this is what I needed: to omit the entire pathname and get only the highest level for every matched result according to the pattern. It meant I had append this option to the command line without any following constructs. Having tested with simpler instances I glanced through the man page and threw in

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-x

to omit constant "/dev/fd 3: not a directory" lines.

So, to sum the entire line that I struggled to come up with to do the task had to be:

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echo PASSWORD | sudo -S find -E -x / -regex '.*(keyword|KEYWORD).*' -and -not -regex '.*(Safari|[Oo]pera).*' -and -not -path *OtherAlwaysShowingUpUselessLine* -prune

Notice that the argument to -path is NOT a regular expression of the extended set with which you'd use -E option to

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find

necessary to provide if

Code:

-regex

is used too. In this case it conforms to the logic nicely and assists in the required manner.

That way I was able to reduce the output to only 5 lines, "sandboxing" that app in the search results that I then had opportunity to apply further actions to.