najogólniejszym
The Polish word "najogólniejszym" is the instrumental singular masculine/neuter form of the superlative adjective "najogólniejszy." This adjective translates to "most general" or "most common" in English. It is formed by taking the root of the adjective "ogólny" (general, common) and adding the superlative prefix "naj-" to indicate the highest degree of generality.
"Najogólniejszym" would be used in a sentence where it describes a noun in the instrumental case. For