I have had a bus card for a couple of years now. Usually it lives in a little plastic pocket to protect it from whatever else happens to be jingling around in my coat pocket--a wallet, keys, the reflector on the string I hang out my pocket to keep my lovely self from being mown down by crazy drivers or bicyclists. The plastic envelop thingy is pretty worn out and ripped up, I need to get another one.
Even if you know the right word, if you don't enunciate properly, it can sound like something you really didn't mean to say.
Plastficka: the little plastic pocket for my bus card
a plastic cunt (I *hate* this word)
Which I really don't need at all. o.O