structure-n; 3 Senses

Sense Number 1: a constructed whole, an edifice

Commentary: STRUCTURE[+concrete][+edifice] A physical edifice, considered as a thing itself, not a property of a thing.
NOTE: Occurs often in the plural.

Examples:
Can you see those three structures to the left of that church spire?
It appears the car hit a hard structure sideways before rolling over across the road.
The structures in their village are all made of local wood.
The chef made a fanciful structure by mounding spun sugar into a tower.
The children built various geometric structures with modeling clay.

Mappings:
WordNet 2.0 Sense Numbers: 1

Sense Number 2: a scheme or system to establish order

Commentary: STRUCTURE[+abstract][+system][+social]
NOTE: usually (always?) occurs in the singular
NOTE: there is an implied (though not usually explicit) agent (e.g. people) which caused the structure.

Examples:
The company is trying to define some structure for its product development work flow.
The structure of Mayan society collapsed after decades of warfare and drought.
The children created structure even in their unsupervised playtime.
These emerging economies still have shaky market structure.
Bees exhibit a fascinating social structure within the hive.
The structure of the EU constitution is very complex.

Mappings:
WordNet 2.0 Sense Numbers: 5

Sense Number 3: the shape or composition of a form

Commentary: STRUCTURE[+quality][+form][+shape/+composition]
NOTE: functions as an attribute or property of some other thing.
NOTE: There is not (usually) an implied agent that caused the structure.

Examples:
These buildings are condemned because their structures are unsound.
There is growing evidence that the structure of space in our universe is three dimensional. I'd say this house has a post-and-beam structure.
His teacher told him there is still no real structure to his musical compositions.
She is studying the structures of quasi-crystals.
His face has well-defined bone structure.
The structure of DNA is a double helix.

Mappings:
WordNet 2.0 Sense Numbers: 2, 3, 4