Question

what does the word perjury mean?
the tactic of deceiving an enemy
the refusal to believe a person who often lies
the crime of lying under oath
the act of telling a white lie

Explanation:

Perjury is a legal term. It specifically refers to the act of lying while under oath in a legal proceeding. The first option is more about a military - like tactic. The second option is about a refusal to believe a person, not a legal definition. The fourth option is about a harmless lie (white lie), not a legal crime.

Answer:

the crime of lying under oath