Noun

1. An advisement providing more up-to-date information than currently known.

   He gave me an update on the situation in New York

2. A change in information, a modification of existing or known data.

   I just made an update to the Wikipedia article on gorillas

3. An additional piece of information. An addition to existing information.

   I just made an update to my blog about my trip to Rome

4. A modification of something to a more recent, up-to-date version; (in software) a minor upgrade.

   Our database receives an update every morning at 3 AM

   I have a couple of updates to install on your laptop

Verb

1. To bring (a thing) up to date.

   I need to update my records to take account of the most recent transaction.

2. To bring (a person) up to date: to inform (a person) about recent developments.

   Update me on what happened while I was away.