One measure of big dog please - I'm returning to my roots

So after 10 years of skivving classes and flunking exams (oral and written) in Singapore, I finally repented and enrolled myself in a Chinese language refresher course -Level 4 Fast Track- at the university's Language Centre last month. That change of heart has probably caused violent twitching in Mdm Wong's eyes (she was our primary school Mandarin teacher whom we once drove to tears with our indifference towards the Mother Tongue).

I can't admit to having reformed entirely, especially after this evening's lesson. Gao laoshi (Teacher Gao) guides us through reading, listening, speaking and writing exercises for 2 hours every Wednesday. Today we came across a particular chenyu (idiom) -dan qiang pi ma- which metaphorically describes tackling a task single-handedly or going into a situation alone, with the implication of having little support behind oneself [geez, isn't it great how I actually SOUND like an English to Chinese zidian (dictionary)].

Laoshi proceeded to define each word in the phrase and emphasised that pi is the term of measurement for a ma (horse), ie. yi pi ma = 1 horse.

"Now it's all well and good that a specific Chinese character evolved through the centuries for sole reference to our equine friends," I thought to myself. "But there has GOT to be more mileage in it!" And so I probed. Sensing an unruly streak of curiosity about, Laoshi's already narrow eyes creased a little more when she saw my hand shoot up.

"Laoshi, when else can pi be used?" I cast her the earnest look of a knowledge-hungry student.

A pause.

"Yi pi luo tuo."

I sniggered - I couldn't help it! With due respect to camels and other largish ungulates, I just didn't see the utility of committing the damn character to memory. There HAD to be some innate logic to it. The Chinese were sensible folks after all ... and how many horses and camels would one cross paths with in a lifetime? The word must, logically speaking, be as effectively applied to somewhat similar creatures, at the very least. So I gave it another stab.

"Na ... yi pi da gou ne?"

Oh, if looks could kill ...