act as

act as

To serve or perform a job or role, often temporarily. Until Kayla returns from her maternity leave, Sharon will act as lead analyst. You will now act as file clerk and benefits coordinator, and your salary will reflect this change.
See also: act
Farlex Dictionary of Idioms.

act as someone

to perform in the capacity of someone, temporarily or permanently; to serve in some special capacity, possibly temporarily. This is Mr. Smith. He'll act as manager from now on.
See also: act
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • set an example
  • keep up an act
  • keep up the act
  • act (up)on (something)
  • act on
  • acting
  • blow job
  • keep an act up
  • keep the act up
  • in the act of (doing something)
References in periodicals archive
This is the unity that is pointed to in an act as exhibition--I show myself; that is sounded in an act as expression--I announce myself; and that is told in an act as connection--I evoke myself.
That is the power of theater, of poetry, of music, of dance, and that is the power of an act as celebration.
In an act as celebration, I learn that experience is not a bargaining ground, a marketplace of give and get.
Only now (and belatedly, some will say) do I attend to the act as doing something.