It often refers to something at the top or extremity of something else.
Here are some examples of words with the root "acro":
* Acrobat: Someone who performs gymnastic feats, often at great heights.
* Acrocephalic: Relating to a head with a high, pointed crown.
* Acropolis: A fortified hilltop in ancient Greek cities, usually containing temples and other important buildings.
* Acrolein: A pungent, colorless liquid found in burnt fats and oils.
* Acromegaly: A hormonal disorder that causes excessive growth of hands, feet, and face.