Butt Call is a term used for an unintended phone call placed by sitting on your cell phone.  Butt call屁股电话，是指坐在手机上面拨打出的电话。Butt call因此成为“误拨电话”的代名词。跟butt call相似的另一个表达是pocket call，即手机放在口袋里不小心碰到通话键而拨出的电话。

Examples:
I butt called my mum by accident. 我不小心给妈妈打了通屁股电话。
I just got a butt call from my boss. I could hear him talking to someone, but he didn’t know his phone had dialed. 我接到老板的一个误打电话。我能听到他正在和别人通话，但他不知道电话已经拨通了。