phrasefunction as function as sth to have a particular use or purpose: The Institute functions as a museum and a centre for research.In the daytime the dining room functions as an office.
function as (something)
To have a particular purpose or fill a certain role. Mrs. Smith will function as your homeroom teacher for the rest of the year now that Mrs. Jones is on maternity leave.
function as
v.
To serve a purpose or play a role similar to that of something else: The beaks of some wading birds function as spears for catching fish.