MySQL speed in relation to rows

[pianoparadise]

I have a database containing about a million nouns like "apple", "orange", etc
My php code would be searching for a particular name in the database like:
SELECT _ from _ where noun="apple". If there are about a million rows in the database, would it take a really long time to find nouns at the very end of the database?

[dagon]

indexed, on descent hardware shouldn't take more than a fraction of a second.

[pianoparadise]

What exactly does indexed mean?

[dagon]

7.4.4. How MySQL Uses Indexes

12.1.8. CREATE INDEX Syntax