The word "elaborate" can be used as both a verb and an adjective, with related but distinct meanings:

As a verb:

• To explain something in more detail or with greater clarity.
  Example: Could you elaborate on your idea? (meaning: please explain your idea more fully)

As an adjective:

• Involving many careful details or complicated parts.
  Example: She wore an elaborate dress. (meaning: the dress had many intricate details)

In summary, to elaborate means to add more information or detail, and elaborate as an adjective describes something that is detailed or complex.