What's the difference between mohammedan and mohammedism?

Mohammedan

Definition:

(a.) Of or pertaining to Mohammed, or the religion and institutions founded by Mohammed.
(n.) A follower of Mohammed, the founder of Islamism; one who professes Mohammedanism or Islamism.

Example Sentences:

(1) After the Westminster terrorist attack last month, one of the party’s MEPs, Gerard Batten, who is Nuttall’s spokesman on Brexit, blamed the attack on Islam , which he called “Mohammedanism”.
(2) In the post on his personal blog written after last month’s terrorist attack in Westminster , Batten said Islam should be referred to as “Mohammedanism – the cult of Mohammed – because that is what it is”.
(3) He continued: “It is a death cult, born and steeped in 1,400 years of violence and bloodshed, that propagates itself by intimidation, violence and conquest.” Batten wrote: “The terrorists are the vanguard of Mohammedanism.
(4) A European gynecologist who takes up his duties in a developing Mohammedan country encounters very different problems compared to those in Europe: Early marriage is customary, the intact hymen has great significance.
(5) The first and last months of the study were Ramadan, the annual period in which Mohammedans abstain from all oral intake during daylight hours and take a single large meal after dark.
(6) They set out to cow the non-Mohammedan population, so that the ‘moderate Muslims’ can get on establishing sharia courts, forcing halal food in school and works canteens, and making the authorities look the other way regarding criminal activities for fear of being called racist and Islamophobic.” Saying that a phobia was a fear without a rational base, Batten said: “A normal non-Mohammedan should have a perfectly rational fear of ‘Islam’.” Play Video 0:36 Protesters ejected from Ukip launch – video The Liberal Democrat MP Tom Brake said: “[Nuttall] must stop turning a blind eye to this blatant Islamophobic language and make clear it will not be tolerated.
(7) It is derived from and is compared with the "Mohammedan praying position".