Which term refers to actions conducted with hidden aims or methods?

The term that refers to actions conducted with hidden aims or methods is "surreptitious." This word is derived from the Latin "surreptitius," meaning to seize or take away secretly. When something is described as surreptitious, it indicates that it is done covertly, often to avoid detection or scrutiny. This could apply to various contexts, such as covert operations, secretive plans, or any behavior that is intentionally concealed to achieve an outcome without drawing attention.

In contrast, the other terms do not carry the same connotation of secrecy or hidden intentions. "Tenuous" refers to something that is weak or insubstantial, often used to describe arguments or connections that lack strength. "Unremitting" describes something that is persistent or relentless, highlighting continuous action without pause, rather than secrecy. "Terse" means being brief or concise in speech or writing, focusing on the succinctness of communication rather than any hidden motives. Each of these terms stands apart from the concept of hidden motives or methods, reinforcing why "surreptitious" is the correct choice.