If you really want to support a charity, do it through their website, not a chugger.
例によって色々なオンライン辞書にあたりました。
Urban Dictionary: Urban Dictionary is a slang dictionary with your definitions.
Charity Mugger. One of those people who stands in the street with a big brightly-coloured bib and quite possibly a clipboard soliticing donations to the Feline Liberation Army or some other worthy cause.
次ぎの説明は上の辞書ではないと思うが出典は記録していません。
Paid "charity" street worker (read: student) who has been trained to believe that they are carrying out a worthy task, improving peoples' lives by conning Joe Public out of their money for this week's Good Cause. Usually an agency worker where the agency takes a hefty cut of the hourly rate that the charity in question has paid for, whilst at the same time increasing profits by selling on details of those foolish enough to actually stop and sign up to said Good Cause.
Wikipediaもチェックしました。
A street fundraiser is a person who collects donations on behalf of a charity. They may be a paid employee of the charity (or a company working on behalf of the charity), or they may be a volunteer .
Paid street fundraisers are sometimes known as chuggers because occasionally fundraising is viewed as aggressive or invasive (a portmanteau of "charity" and "mugger"). It became popular as a way of referring to street fundraisers after several articles appeared in British newspapers
"chuggers"は"smog" の様にいわゆる鞄語(例 "smoke + fog")でイギリス生まれの新語でした。