Actual usage of 企てる 企てる #sentences - Jisho.org
does not appear to support the plain english definition of ‘plan’ either.
She attempted suicide.
He contrived to cheat in the examination.
An investors’ group is attempting a leveraged buy-out of the firm.
It appears that other synonyms such as “attempt” are more accurate, though also not exact. It’s good to remember that one-to-one translations between languages rarely exist, especially when they don’t share roots (such as latin)