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aids, in feudalism

(Encyclopedia)aids, in feudalism, type of feudal due paid by a vassal to his suzerain (overlord). Aids varied with time and place, although in English-speaking countries aids were traditionally due on the knighting...

AIDS, in medicine

(Encyclopedia)AIDS or acquired immunodeficiency syndrome, fatal disease caused by a rapidly mutating retrovirus that attacks the immune system and leaves the victim vulnerable to infections, malignancies, and neuro...

castor, in zoology

(Encyclopedia)castor: see beaver.

category, in philosophy

(Encyclopedia)category, philosophical term that literally means predication or assertion. It was first used by Aristotle, whose 10 categories formed a list of all the ways in which assertions can be made of a subje...

category, in taxonomy

(Encyclopedia)category, in taxonomy: see classification. ...

boulder, in geology

(Encyclopedia)boulder, large rock fragment formed by detachment from its parent consolidated rock by weathering and erosion. In engineering and geology, especially in the United States, the term is applied to loose...

bow, in music

(Encyclopedia)bow bō [key], implement used in playing stringed instruments. Its name originated from the fact that in its early form it resembled an archer's bow, but by the 17th cent. the European bow had gradual...

brake, in botany

(Encyclopedia)brake, in botany: see bracken.

brake, in technology

(Encyclopedia)CE5 Shoe brake CE5 Disk brake brake, in technology, device to slow or stop the motion of a mechanism or vehicle. The vacuum brake system, or vacuum brake, depends upon the use of a vacuum to ...

sol, in chemistry

(Encyclopedia)sol, in chemistry: see colloid.