browser.search.suggest.enabled = false
Or, if you mean that you'd like to have autocomplete on for searches, just leave the default: browser.search.suggest.enabled = true
This does not affect the URL bar. nnoremap g gj
nnoremap k gk
That's it, once and done. Aside from setting your wrap preferences—which you would have had to do anyway with hard wraps—there's no more to be taken care of. The text will always display fluently and in full, and you will have no need to manually reformat your paragraphs using gqap whenever you make a change to them. All that need concern you is the text, not its line-by-line arrangement.
Perhaps you mean that 'apple' has a different meaning in the United States than, say, in Wales, because its web of implications looks different in one place than another. Following that thought, though, the same would be true of two American speakers, who surely have their own idiosyncratic webs. It's an interesting idea. But are words not 'synonyms' that have the same referent, only because two speakers have different relationships to that referent? Is a word partly its evocation? Or can we look at its evocation separately from a stricter 'meaning' it shares between speakers? (Surely it shares something, or language would lose its point.)
Incidentally, synonym is not the word to be nullifying here. A synonym is a like word, something that may equal the original but usually differs in degree, amount, tone, allusion, or other effect. Anyone using a thesaurus without a dictionary is sure to embarrass themselves sooner or later: differences in meaning between like words are common, and it is no revelation to say that one speaker will have different associations with a word than another, particularly if they come from different cultures.