Ksi (Ѯ, ѯ) is a letter of the early Cyrillic alphabet, derived from the Greek letter Xi (Ξ, ξ). It was mainly used in Greek loanwords, especially words relating to the Church.
Ksi was eliminated from the Russian alphabet along with psi, omega, and yus in the Civil Script of 1708 ( Peter the Great's Grazhdanka), and has also been dropped from other secular languages.
It represented "60" if used as a number.
KSI may refer to:
- KSI (entertainer), English YouTube celebrity and rapper referred to as KSI
- ksi (unit), kilopound per square inch, a non-SI unit of stress or pressure
- Knight Companion of the Order of the Star of India
- Killed or Seriously Injured, in road safety
- Kontoret för Särskild Inhämtning, "The Office for Special Collection", a Swedish intelligence agency
- the IATA code for Kissidougou Airport
- KSÍ , Football Association of Iceland
- Ksi (Cyrillic letter)
, pronunciation of Greek letter Ξ or ξ in IPA symbols
Olajide "JJ" Olatunji (born 19 June 1993), better known as KSI (a shortened version of his online aliasKSIOlajideBT), is an English rapper, comedian, actor and YouTube personality. Alongside music, he is well known on YouTube for his channel, which has, as of August 2016, reached over 14 million subscribers and 2.8 billion video views.
The pseudonym "KSIOlajideBT" comes from a gaming community he was in (KSI), his given name Olajide, and BT British Telecom, according to his website. His videos mostly consist of FIFA gameplay/commentary, whilst playing other games on various platforms with the occasional vlog.