as

Conjunction / Adverb / Preposition
  1. used to indicate similarity or equality Conjunction / Adverb / Preposition
    She is as tall as her brother.
  2. while; during the time that Conjunction / Adverb / Preposition
    As I was leaving, it started to rain.
  3. in the role of; in the capacity of Conjunction / Adverb / Preposition
    He works as a teacher.
synonyms: like, such as, while