Etymology
Advertisement
aristo- 

word-forming element meaning "best," also "of the aristocracy," from Greek aristos "best of its kind, noblest, bravest, most virtuous" (of persons, animals, things), originally "most fitting," from PIE *ar(ə)-isto-, suffixed (superlative) form of root *ar- "to fit together."

Related entries & more 
Advertisement
arterio- 

word-forming element meaning "arterial," from Latinized form of Greek arteria "windpipe; artery" (see artery).

Related entries & more 
arthro- 

before vowels arth-, word-forming element meaning "pertaining to the joints," from Greek arthron "joint," from PIE *ar(ə)-dhro-, suffixed form of root *ar- "to fit together."

Related entries & more 
as- 

assimilated form of ad- before -s-.

Related entries & more 
at- 

assimilated form of ad- "to, toward, before" before stems beginning in -t-; see ad-. In Old French and Middle English regularly reduced to a-, later restored.

Related entries & more 
Advertisement
atelo- 

word-forming element meaning "imperfect development or structure," from Greek atelēs "imperfect, incomplete," literally "without an end," from a- "not, without" (see a- (3)) + telos "the end, fulfillment, completion" (see telos).

Related entries & more 
atmo- 

word-forming element meaning "vapor," from Greek atmos "vapor, steam," which is of uncertain origin. Watkins has it from PIE *awet-mo-, from root *wet- (1) "to blow" (also "to inspire, spiritually arouse;" see wood (adj.)). Beekes says it is not considered to be related to the source of atman.

Related entries & more 
atto- 

word-forming element meaning "one quintillionth," 1962, from Danish atten "eighteen" (a quintillion is 10 to the 18th power), related to Old English eahtatene (see eighteen).

Related entries & more 
audio- 

word-forming element meaning "sound, hearing," from combining form of Latin audire "to hear" (from PIE root *au- "to perceive"); used in English word formation by 1890s.

Related entries & more 
Austro- 

combining form meaning "Austrian;" see Austria.

Related entries & more 

Page 5