背く

1. Origins, structure, and basic meaning

• Structure: 背く, read そむく, joins the turning-away or defiance stem 背 with the verb ending く.
• Basic usage: It means acting against a rule, order, or expectation, as in 命令に背く or 期待に背く.

2. Common pitfalls and similar expressions

• Grammar and combinations
  • The defied target takes に, and figurative disobedience is more central than the physical act of turning one's back.