1. Descriptive of or related to that which is first in a list or is the earliest in a sequence: Tim and Jordan just started their primary training for snow boarding.
2. Something that is not coming from or is not dependent on anything else: The contents of the book is based on primary sources instead of secondary sources of information.
3. A reference to the most important thing: Good health is the primary concern of Brenda for her two sons, Dirk and Gary.

Medical support from a doctor who diagnoses a patient's condition first and then provides basic treatment or makes a decision that the patient should see a medical specialist: Mary's doctor provides primary care for many people who cannot normally pay for such treatment.

1. An electrical cell that uses an irreversible chemical reaction to generate electricity and, as a result, cannot be recharged: When buying new batteries for her flash light, Linda debated whether to buy primary cell batteries or to invest in rechargeable batteries.
2. A cell consisting of two dissimilar metal electrodes in a solution that acts chemically on one or both of them to produce a voltage: Jack, the auto mechanic, stated that the battery or primary cell in the car was dead and could not be recharged; so, it would need to be replaced.

Primary cosmic rays are submicroscopic, electrically charged particles, largely protons, that travel in space at speeds nearly equal to that of light.

The first of a process of changing the properties or characteristics of chemical matter through incident radiation: Jane and the students in the chemistry class were expected to write the formulas for primary ionization of specific chemical elements.

A psychoanalytical or medical term referring to the initial, or early, beliefs by an individual that his or her self-centeredness, conceit, and ego are more important than those of others: It was a difficult diagnosis to accept, but Hans was able to understand the notion of primary narcissism as it related to his personality and he vowed to try to change his attitudes about himself and other people.

One or several impairments in visual recognition without any apparent damage of intelligence, motivation, or attention when vision is usually intact and the mind is clear: Individuals who are diagnosed with primary visual agnosia find that objects may be identified by touch, sound, or smell. They may not be able to identify a set of house keys by sight; however, it is possible for the person to recognize the keys when they are held in his or her hands.