随便(suíbiàn) Casual/Informal
The character “随(suí)” means to comply with and “便(biàn)” means convenience.
Example:
他平时着装很随便,从不讲究。
Tā píngshí zhuózhuāng hěn suíbiàn, cóngbù jiǎngjiu.
He usually dresses casually and never pays much attention to the way he dresses.