数学里说的cos 是cosine(没有两个s喔)
应该不是because 的缩写吧,因为一般会写做 coz.
还有以下几种可能性:
Cosmic Origins Spectrograph
Class of Service
Chiefs of Staff
Class of shares
Chief of Security
Crypto Operating System
参考资料：google
COS
=Cash On Shipment 装货付款
或[数](=cosine)余弦
COS=Cash On Shipment 装货付款
because