An excellent performance. / Someone or something whose performance is excellent. / (sometimes sarcastically) Someone or something who is generally well-mannered, conscientious, etc.

(law) An unforeseen occurrence beyond one's control, such as a natural disaster. / Used other than figuratively or idiomatically: see act, of, God.

(pharmacology) Having a pharmaceutical effect principally in the short term.

(linguistics) An act carried out by speech, such as promising, ordering, greeting, warning, inviting and congratulating.

To behave timidly, reluctantly, or afraid, especially when confronted with something new or unfamiliar

Applying power in two directions. / Producing a double result.

To hold an academical disputation.

Any legislation that requires a tax to be paid on the transfer of certain documents.

(euphemistic) sexual intercourse

simple past tense and past participle of act upon