Hint #1
The word “maneuver” is a synonym for the nine-letter word.
The nine-letter word is NAVIGATOR.

There are other words with less letters.  The ones that we recognize as commonly-known words are:
aorta, aviator, grain, grant, groan, groin, intro, orating, organ, rating, ratio, ration, raving, roving, tiara, train, vagrant, variant, and vigor.

That’s 19 words, but the English dictionary recognizes up to 39 words total.  Can you find all of them?