bontoshter adjective 1noun 1forms 3 adjective1 •(slang, no longer used) Excellent; wonderful.‘Ah me! I’m his bonzer tart! Ah me! Ah me!’ ‘You are! You are! My bontoshter bit of fluff!’ — 1910 noun1 •(slang, no longer used) Someone or something impressive and wonderful.The ‘Dilly Ooze’ says the Russian Baltic Fleet is bombarding Varna. We heard the Russians had some new long range guns. They must be bontoshters! — 1915 formsbontoshters · more bontoshter · most bontoshter