Sentence:  The word "trust" is in no way a neologism. On the contrary, it is a kind of <WSD>paleologism</WSD>, a primitive signifier, "a word from a barbarian time." 
Meaning of the word marked with <WSD> tags:  A word or phrase that was coined in the distant past, often now obscured, or if recently used: possibly having a definition or implication different from that of any earlier usage.