In general, mucker is a type of front-end loader that moves broken rock onto a belt conveyor, which dumps it into a car or truck transportation system. As all operations are concentrated on the runway, congestion is chronic and a lot of ingenuity is put into planning. His voice had a hint of bitterness; She didn`t like coming as a mucker, and she hadn`t been told she couldn`t take the exams. Thank you, not always – I`ve been a bastard more than once in my life! Anyone would have done it, anyone who wasn`t a mucker, I mean. The mucker in the mine must belong to the same union as the man operating the drill. I totally agree, Conan! It is highly unlikely that Mucker comes from mo chara. I would have thought that the word “mucker” is almost certainly of Germanic origin. In Dutch, the word “Makker” means a friend, a friend and is pronounced identically with the cockney “mucker” By the way, while researching this post, I noticed that others say that mucker comes from the Irish mo chara, which means my friend. This, too, is absurd. As any competent Irish speaker will tell you, this is a Chara, not Mo Chara, if you speak directly (i.e. vocivocally) with your friends.
Of course, it is perfectly acceptable to speak of people in the third person who use mo chara, but that would hardly lead to a loanword, since mo is not inextricably related to the word cara. Only the basic form of the word, cara, would be borrowed in a bilingual situation. For example, we`ve all heard French-speaking characters in movies say things like, “How are you, my friend?” It is a vocative usage, like “a chara”. But when the Spanish word amigo is used in English, it is always simply used as amigo, never as mi amigo or su amigo, and so it is quite reasonable to assume that people might say things like “he is a great cara of me”, but not *`it`s good to have a mo chara` (or chara or ár gcara, for that matter). And it doesn`t even affect the issues of debate. Mo chara, when pronounced correctly, something like mohara is pronounced to rhyme with Sahara. What would it be like a mucker? Cassidy suggests that mucker, a word colloquially used in Ireland and England to mean partner or friend, comes from the Irish Mucare, meaning “pig” of muc. According to Dineen, the word mucaire means a pigcherd, a boorish, a rustic.
Ó Dónaill`s dictionary only gives the meaning of “a sloppy worker”. How you go from one of these meanings to the concept of partner is incomprehensible to me. Muckern is the nickname of the disciples of the teachings of Johann Heinrich Schönherr (1770-1826) and Johann Wilhelm Ebel (1784-1861).  The word comes from the Middle German word muckern, which was also used for cleaning stables and stables. In some parts of Germany, the word smuggling was written.  I don`t think there is much doubt about the Germanic origin – for me, English is just a Germanic dialect! Your suggestion about Makker is certainly interesting. I tried to look for an etymological dictionary of the Netherlands, and it seems to be of Frisian origin and dates from at least the late 16th century, so it seems reasonable. The problem is that if you look at a lot of these terms (take buddy, for example), there are a lot of reasonable candidates for the origin. One thing is certain, neither the Irish Mo Chara nor the Irish Mucai are strong candidates for the origin of the Mucker.
Back in the real world, muck is a very old word in English (derived from Old Norse), which means dirt. A mucker is someone who works with this dirt (like a mucker-out), but this is probably not directly the origin of the mucker in the sense of friend. To do this, we need to look at how people often play or play with each other. That`s why we have muckers. It is therefore much more likely that the word mucker in all its meanings is a reference to the English muck + er than that it has a connection with Mucaire. As usual, Cassidy ignores the obvious English explanation for a fragile derivation of Irish.