Difficult to control or noisy.
1) The room was full of obstreperous children.
2) An obstreperous crowd protested against the goverenment's new immigration policy.
Latin obstreperus, from obstrepere which means 'to clamour against', from ob- which means 'against' + strepere which means 'to make a noise'.
blatant, clamant, clamorous, yowling
amendable, biddable, compliant, conformable, docile.