“As” have different meaning depending on the position. In the current sentence, yes you can replace by “while”. But you can find other usage (I quote from internet grammar guide) : —— As as a preposition — We use as with a noun to refer to the role or purpose of a person or thing: I worked as a waiter when I was a student. Most of us did. — - As as a conjunction — The conjunction as has several different meanings. We use as when one event happens while another is in progress (‘during the time that’). In this case the verb after is often in the continuous form: They arrived as we were leaving. (time conjunction meaning ‘while’ or ‘when’) We use as to connect a result with a cause: I went to bed at 9 pm as I had a plane to catch at 6 am. (reason and result meaning ‘because’) — As: simultaneous changes —- We use as to introduce two events happening at the same time. After as with this meaning, we usually use a simple (rather than continuous) form of the verb: As the show increases in popularity, more and more tickets are sold daily.

Hi Teresa Yes, you could use while, since and other synonyms

>>LDOCE6 Thank you. I used the site of the dictionary LDOCE for the first time. I like it. :) Have a nice weekend!

Thank you Matthew. Those your examples below are helpful, so I understood that the "as" meant "while". :)

that was the fourth meaning of the word in LDOCE6