What is the meaning of Be_up_to?

Used other than figuratively or idiomatically: see up, to.

Capable, ready or equipped, having sufficient material preconditions for, possibly willpower (at a particular moment).

As much as; no more than .

Until.

Within the responsibility of, to be attributed to the sphere of influence of, having someone or something as authoritative in.

Doing, involved in.

Devising, scheming (planning something mischievous or inappropriate).

Considering all members of an equivalence class the same.

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Familiar with the meaning of; able to understand.

Taught by; in the class of.

Source: wiktionary.org