MISC = miscellaneous.
It's the abbreviation you see (1099-MISC) when you work for someone and they send you a record of all the money they paid you throughout the year.
It gets reported on your tax return and you pay federal tax and maybe self-employment tax too, depending on how you received the money.
Did you receive one this year for 2017?
If you did, and need help inputting it, post back to this thread.