Select the correct one-word for the given group of words: One who knows…

Solution: The correct one-word substitute for "One who knows everything" is Omniscient.

Meaning and example:

• Omniscient — having or seeming to have unlimited knowledge. Example: God is omniscient.

• Omnipresent — present or having an effect everywhere at the same time (incorrect for this prompt).

• Omnipotent — having unlimited power or ability to do anything (incorrect for this prompt).

• Omnivorous — able to eat both plants and meat; relates to diet, not knowledge (incorrect for this prompt).

Tip: The prefix "omni-" means "all." Combine it with the root relating to knowledge to identify the correct word.

Therefore, the correct answer is Omniscient.