Definition from Wiktionary, the free dictionary
Alternative forms 
- Rhymes: -uːθ
- (UK, Australia, New Zealand) A mild oath expressing surprise or generally adding emphasis.
- Strewth! I guess I′ve been too trigger happy!
- 1957, Greta X (Angela Pearson), The Whipping-Post, page 109,
- “Strewth! Here she is,” said the salesman.
- 1971 July 1, Michael O′Donnell, Take to the hills, New Scientist, page 41,
- “Strewth,” he whistled. “I reckon that′s a complicated fracture of the right tibia.”
- 2007, Marilys Edwards, Keep The Home Fires Burning, AuthorHouse, page 187,
- He smiles and is going to say something encouraging. Strewth! Why doesn′t he duck? His head′s above the parapet. He′s in the line of fire. Silly BUGGER! “CRACK!”