轻信

轻信	qīng xìn	to easily trust; gullible; naïve
轻	qīng	light / easy / gentle / soft / reckless / unimportant / frivolous / small in number / unstressed / neutral / to disparage
信	xìn	letter / mail / CL:封 / to trust / to believe / to profess faith in / truthful / confidence / trust / at will / at random