'mosha' is an insult used by chavs
to describe individuals who decide to wear non-sporty clothes brands such as reebok and nike. Most of those people who are pidgeon-holed by chavs/townies as 'Moshas' do not consider themselves as 'moshas'. As most intelligent people know, there are many different types of styles and musical influences within the category of 'mosha', such as emo
, grunger, Metalhead, goth etc.
Those poeple who are defined as 'moshas' by chavs/townies just like to listen to the insults and subtly outwit them and/or just walk away thinking how childish the chavs really are.
Anyone with hair that grows longer than their ears are usually called 'moshas' by chavs/townies and are told to "get a fukin hair cut, fukin mosha"
A "mosher" could be referring to someone who involves themselves in mosh pits
in rock concerts, but it is most commonly used as a chav insult to anyone who listens to "mosha music" (i.e. anything that isn't in the charts)