Mid
Mid may refer to any of the following:
1. In Microsoft Excel and spreadsheets, MID is a function that extracts characters from a cell value. For example, the following formula looks at the A2 cell value and extracts 8 characters from its value, starting at position 1, which is the first character. If the value in cell A2 is "Computer Hope," the formula extracts the characters "Computer" from that value.
=MID(A2,1,8)
See the following link for further examples and information with this function.
2. When describing a file, .mid is a file extension for a MIDI (Musical Instrument Digital Interface) file.
3. With chat, mid is short for "middle" and describes anything average or below average. For example, a YouTuber may ask her audience to rate her outfit, and some may say it's "mid" to indicate it's ok but not great.