Extremely small, metabolically inert microorganisms composed of a short strand of either DNA or RNA within a protein coat, and, in some, a surrounding envelope; they replicate only within the cells of living hosts, primarily plants, animals, and bacteria, taking over the nucleus and directing it to produce viral proteins and DNA or RNA. They frequently cause disease in their hosts. Viruses occupy a special taxonomic position: they are not plants, animals, or prokaryotic bacteria (single-cell organisms without defined nuclei), and they are generally placed in their own kingdom. In fact, viruses should not even be considered organisms, in the strictest sense, because they are not free-living, meaning they cannot reproduce and carry on metabolic processes without a host cell.

Virus(kingdom)　(P,,U,English-P,D,U,N)
Virus(kingdom)　(P,,U,Latin-P,D,U,N)
viruses(,U,English-NP,AD,U,N)
virus(,U,English-NP,AD,U,N)
病毒界(界)　(P,,U,Chinese (traditional)-P,D,U,U)
病毒(,U,Chinese (traditional)-NP,UF,U,U)
ping tu chieh(P,,U,Chinese (transliterated Wade-Giles)-P,UF,U,U)
bìng dú jiè (P,,U,Chinese (transliterated Hanyu Pinyin)-P,UF,U,U)
bing du jie(P,,U,Chinese (transliterated Pinyin without tones)-P,UF,U,U)

Top of the AAT hierarchies
....Agents Facet
........Living Organisms
............Virus (kingdom)

meaning/usage overlaps with....

microorganisms

Chinese (traditional)....	極微小且新陳代謝遲緩的微生物，由一股DNA或RNA所組成，外面包覆一層蛋白質外殼，有些病毒還有一層包膜；它們僅於活體宿主的細胞中繁殖，而宿主主要為植物、動物以及細菌；它們會控制宿主體內細胞的細胞核，並使細胞核開始製造病毒蛋白質以及DNA或RNA，經常導致宿主感染疾病。病毒在分類上佔有特殊位置，因為並非植物、動物或單細胞細菌(即不具明顯細胞核的單細胞有機體)，而被歸為獨立的一界。實際上，病毒甚至不應被視為有機體，因為它們不能單獨存在，如果沒有宿主，它們便無法繁殖與進行新陳代謝。

Virus(kingdom)............	[VP]
.................	Natural History Museum, London (2000-)
.................	Biodiversity Heritage Library (2005-)
.................	Encyclopedia Britannica Online (2002-)
viruses............	[VP]
.................	Encyclopedia Americana (1985) 1:859
.................	CDMARC Subjects: LCSH (1988-)
.................	MeSH (1979-) MeSH classification number B4
.................	Oxford English Dictionary (1989)
.................	Judge and Toyne, Oxford Illustrated Encyclopedia (1985) 2:356
.................	Webster's Third New International Dictionary (1961)
.................	Random House Unabridged Dictionary (1993)
.................	Oxford English Dictionary Online (2002-)
virus............	[VP]
.................	Getty Vocabulary Program rules
病毒界(界)............	[AS-Academia Sinica]
.................	國家教育研究院－雙語詞彙、學術名詞暨辭書資訊網 December 21, 2012
.................	智慧藏百科全書網 December 21, 2012
.................	基礎生命科學 2

Getty AAT: 300249621 Getty AAT: http://www.getty.edu/vow/AATFullDisplay?find=costume&logic=AND¬e=&subjectid=300249621
ASDC Union Catalog： Virus 、viruses 、virus 、Virus 、病毒界 、病毒 、ping tu chieh 、bìng dú jiè 、bing du jie