@ACB,
ACB one should remember that language does not follow the rules of formal logic. One has to not only take into account the context of any given utterance as well as any normal inference that any given utterance may express. Unlike in logic a proform (a non-specific form that stands for a specific form) can represent an implied antecedent (that which is represented by a proform). Also remember that words function as meaning containers, their form is arbitrary. Also remember that a dictionary definition is not a functional definition.
Sentence: Billy is nowhere to be found.
Part of speech (nowhere) adverb modifying where Billy is/is not found. unlike with nothing which is a pronoun and represents the absence of a thing nowhere is an adverb modifying the the verb to find. We are not referencing an actual place per se we are representing the modification of how the verb happened which was searching place to place to place.
Context: If billy can be found nowhere. find being in the past tense means that there was a search and in all the places searched Billy was not in them. So all the places searched should be represented somewhere in the sentence to communicate that the finding was unproductive. the places cannot be represented by [Billy] or [is], or [to] or be or [found], which leaves [nowhere] to represent the modification of to find or where billy isn't that was searched.
Semi definite (read prior post please): the term nowhere creates a boundary of all the places searched that billy was not found. This leaves billy somewhere else, obviously. so nowhere's antecedent is all the places searched that Billy was not found that can be expressed as everywhere Billy wasn't found.
@Ken I understand you are not capable of understanding anything you don't agree with. I also understand you are not capable of understanding that people operate under other forms of logic than standardized formal logic mostly because you disagree with it. So feel free to to rant and piss and moan about jargon all you want, as you can see, any jargon I may have used in the above post was clearly defined.