Learn how to say Obstreperously correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word obstreperous:
noisy and difficult to control:
the boy is cocky and obstreperous
late 16th century (in the sense ‘clamorous, vociferous’): from Latin obstreperus (from obstrepere, from ob- ‘against’ + strepere ‘make a noise’) + -ous