berkoadj.
/ˈbəːkəʊ/, U.S. /ˈbərkoʊ/, Australian English /ˈbɜːkoʊ/, New Zealand English /ˈbɜːkʌu/ Australian and New Zealand.
Out of control with anger or excitement. Chiefly in to go berko.
ΚΠ
1961 B. Crump Hang on a Minute Mate 163 He's okay when he's sober but when he's got a few in he goes berko.
1989 Pacific Way Jan. 11 If I continue in this vein, suggesting that most New Zealandisms are in truth simply mistakes, my compatriots will go berko at me.
2001 Sunday Mail (Brisbane) 4 Nov. 61/2 Plot: One woman drives three blokes berko.
2015 A. Carter Bad Seed 241 The dog down the road was going berko.
This entry has been updated (OED Third Edition, June 2019; most recently modified version published online December 2021).
<
adj.1961