The phrase witr or pronounced as وَتْر / وِتْر - watru and witru literally means single (odd numbers) which is the opposite of the phrase shafa’ (even numbers). While technically, it means: “A specific prayer performed in a specific time as the closing of the night prayers, whether it is done in the beginning, middle or end of the night”. The numbers of its rak'ah is odd numbers and that is why it is named as witr.
"Anyone who has a brain should nourish his intellect just as he nourishes his stomach and there is no better way to nourish the mind than reading a book and benefiting from it. Read whatever you can get your hands on, even if it's a cookbook."
A student of knowledge can forget anything, but should never forget sending salutations upon the Prophet ﷺ whenever and wherever his name is read or mentioned.