Ok, I assume this is in Canada based on your profile so you have several options (take none of these seriously) :
1) Go to the grocery store and find something American which is labeled in pounds. Take it to the produce section and put it on the scale. Do the math and buy the equivalent in zuchini.
2) Assuming you already have the zuchini or are buying it from an open market or such: do 1) above except buy something else that you might like as a side dish. Come home and cut apart a coat hanger to make a primitive balance and use it to weigh out an equal amount of zuchini.
3) 1 gallon of water weighs about 8.5 pounds. Estimate 1/8.5 gallon of water, take to grocery store, put on scale, buy equivalent of zuchini. Oh wait, if you can't measure a pound, you probably can't measure a gallon either...
4) Cross the US border. Buy 1 pound of zuchini, go home, cook. Hmmmm... Maybe you need to buy 1.5 pounds due to the exchange rate. (Sorry, I admit that was a little cold.)
6) Go to McDonalds, buy 4 quarter pounders, put them on the scale, no, wait, eat them and you won't be hungry for zuchini any more. Eat a "pound cake" as dessert just to feel good about it.
6) Ask your neighbor for 1 pound of zuchini. Let him figure it out.
7) Use 1 kilogram = 2.2 pounds as a conVersion factor. (use this only as a Last resort)
8) Come on, man! This is cooking! Just grab a couple of handfuls and throw them in!
Slick.