Deku is a Japanese word that means ‘one who can’t do anything’. It can be associated with the phrase ‘Deku no bou’ which translates to ‘good for nothing’ or ‘blockhead’. The word can be derived from the Japanese word: (木偶の坊 ) which translates to mean, a wooden doll, but has been also known to mean a useless or good for nothing person.
The word Deku originates from the popular super hero anime and manga, Boku no Hero Academia. The series is written and illustrated by Japanese mangaka, Kōhei Horikoshi.
The series has been serialized since July 2014 in the Weekly Shōnen Jump. The main character and hero of the series, Izuku Midoriya, is given the nickname Deku by his childhood friend, Bakugo. It was used as a term of mockery towards Izuku. Furthermore, when reading the kanji for the name Izuku (出久) in reverse, it turns to the name Deku, hence solidifying the meaning behind the name Deku.
Later on in the series, it is noted that the name Deku sounds similar to the Japanese word: Dekiru, which is used to express the ability to do something.