Sober posture (anag) — unruly

• Unruly old boy upset superstore
• Noisily aggressive
• Set super booster to 'loud'
• Noisy and unruly

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
c.1600, from Latin obstreperus "clamorous," from obstrepere "drown with noise, make a noise against, oppose noisily," from ob "against" (see ob- ) + strepere "make a noise," from PIE *strep- , said to be imitative (compare Latin stertare "to snore," Old ...

Longman Dictionary of Contemporary English Word definitions in Longman Dictionary of Contemporary English
adjective EXAMPLES FROM OTHER ENTRIES ▪ Some children placed on the drug became more subdued, less obstreperous . EXAMPLES FROM CORPUS ▪ Out of power, he has been just as obstreperous , if somewhat less visible.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Obstreperous \Ob*strep"er*ous\, a. [L. obstreperus, from obstrepere to make a noise at; ob (see Ob- ) + strepere to make a noise.] Attended by, or making, a loud and tumultuous noise; clamorous; noisy; vociferous. ``The obstreperous city.'' --Wordsworth. ...

WordNet Word definitions in WordNet
adj. noisily and stubbornly defiant; "obstreperous boys" boisterously and noisily aggressive; "kept up an obstreperous clamor"

Wikipedia Word definitions in Wikipedia