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(lav′ĕn-dĕr) [Fr. lavendre, fr L. lavendula, livendula] An aromatic, flowering plant (Lavandula angustifolia Miller) whose essential oils are used for bathing, perfuming, and making ointments. Some people develop allergic reactions on contact.


(lo) 1. A scientific statement that is found to apply to a class of natural occurrences. 2. A body of rules, regulations, and legal opinions of conduct and action that are made by controlling authority and are legally binding.

administrative l. The body of law in the form of decisions, rules, regulations, and orders created by administrative agencies under the direction of the executive branch of the government used to carry out the duties of such agencies. Regulations of nursing practice are considered administrative laws.

all-or-none l. The weakest stimulus capable of producing a response produces the maximum contraction of cardiac and skeletal muscle cells, and the maximal impulse transmission rate in neurons.

apology l. A colloquial term for any legal statute that encourages health care providers to acknowledge and disclose medical errors openly. Although apology laws vary from one jurisdiction to another, most include some measure of legal protection for the individual or agency making the apology.

Avogadro l. SEE: under Avogadro, Amedeo.

Beer l. SEE: Beer law.

Bell l. SEE: under Bell, Sir Charles.

biogenetic l. The discredited theory in embryology that ontogeny recapitulates phylogeny, i.e., an individual in its development recapitulates stages in its evolutionary development. SYN: Haeckel law.

Boyle l. SEE: Boyle law.

case l. Opinions or decisions made by the courts.

Charles l. SEE: Charles law.

common l. A system of law that originated in medieval England and is based on former legal decisions (precedent) and custom, not on legislation. Common law constantly evolves from previous decisions and changing custom. It forms the basis of the legal system in the U.S. (except Louisiana), the U.K. and most other English-speaking countries and is therefore the most frequent source of legal precedent for malpractice cases.

cosine l. 1. A mathematical law that describes the relationship between the sides and angles of any triangle. 2. In radiological treatment, the effectiveness of radiant energy and the angle at which it strikes tissue. The maximum amount of energy transfer occurs when the energy strikes tissue at a 90° angle. As the angle changes, the effectiveness of the energy is reduced by the multiple of the cosine of the angle: Effective energy = applied energy × cosine of the angle.

l. of contiguity 1. A law stating that if two ideas occur together, then the recollection of one will likely stimulate recall of the other. ...

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