late 14c., "to mitigate, diminish" (transitive), from soft (adj.) + -en (1). Meaning "to make physically soft" is from 1520s; intransitive sense of "to become softer" is attested from 1610s. Soften up in military sense of "weaken defenses" is from 1940. Related: Softened; softening.
实用例句
1. To soften a formal look, Caroline recommends ethnic blouses.
为了看上去不过于正式，卡罗琳建议穿有民族色彩的上衣。
来自柯林斯例句
2. If they'd treated you well it was just to soften you up.