polarity-n; 3 Senses

Sense Number 1: any two things, traits in a relation of diametrical opposition

Commentary: POLARITY[+relation][+diametrical][+contrast][+opposition]
NOTE: implies -two- entities, concepts, traits in opposition to each other

Their world view postulates a fundamental polarity between male and female.
The Cold War's clear-cut polarities no longer define political reality.
He viewed it as a balanced polarity between good and evil.

WordNet 3.0 Sense Numbers: 1

Sense Number 2: the state of an electromagnetic charge

Commentary: POLARITY[+state][+charge][+electromagnetic][+positive/+negative]

The strength of the magnetic field peaks immediately after switching polarity.
It exhibits polarity when presented to a magnetic needle.
He got the polarity of the battery reversed.

WordNet 3.0 Sense Numbers: 2

Sense Number 3: organism's differentiation of its structure via growth

Commentary: POLARITY[+quality][+structure][+differentiated][+growth][+biological]
NOTE: refers to differentiation in organic physical structures, usually exhibited at the ends of the structure.

The polarity of this fly is evidenced by the difference in the anterior and posterior sections of the body.
It's an undifferentiated mass of cells without noticeable polarity.

WordNet 0.0 Sense Numbers: 1c