1. verb To call someone on the telephone. In this usage, a noun or pronoun can be used between "dial" and "up." Well, then dial Joe up and see what he has to say about all this!

2. noun A method of connecting to the Internet via a telephone line. In this usage, the phrase is usually hyphenated. Remember the terrible sound that dial-up used to make? Yikes.

3. adjective Describing a method of connecting to the Internet via a telephone line. In this usage, the phrase is usually hyphenated. Remember how slow dial-up Internet used to be? Yikes.