quack

if it looks like a duck and walks like a duck, it is a duck

If something has all the characteristics of a thing, it is probably that thing, regardless of what it is called or presented as. There are many variations of the expression, and it is often shortened to the first part of the phrase. They say it's not a tax, but if it looks like a duck and walks like a duck, it is a duck.
See also: and, duck, if, like, look, walk
Farlex Dictionary of Idioms.

quack

n. a fraudulent physician; a derogatory term for a physician. I won’t go back to that quack ever again!
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • if it looks like a duck and walks like a duck, it is a duck
  • tell me about it
  • have a thing
  • far be it for/from me to...
  • far be it from
  • far be it from (one) to (do something)
  • far be it from me
  • far be it from me to
  • far be it from me to do something, but...
  • far be it from one to
References in periodicals archive
In last nine months, more than 400 cases have been registered against quacks and their clinics were sealed but they open businesses again despite the cases.
Quackery goes on unabated in Muzaffargarh district
A study conducted a couple of years ago pointed out that a number of people in this tehsil had been suffering from hepatitis C one of the major causes of which is said to be administration of treatment by quacks.
Quackery ails health sector
The bereaved parents and residents of the area demanded immediate arrest of the quacks and stern punishment for them.
Girl falls victim to quacks
Quick Quack Car Wash has a record of sponsoring local events and athletic programs as well as contributing to community groups' fundraising efforts.
Quick Quack Car Wash Celebrates Grand Opening of the First of Ten Utah County Locations with Ten Days of Free Car Washes
initiate any enquiry against such quacks. " But in this case it was compulsory to complete the enquiry within 72 hours.
Kejriwal acts tough on Capital quacks
Barker's successes after many doctors had failed, under the title: "What is a quack?" The general public stood firmly behind Mr.
Running after quacks and mountebanks ..
The scientists' conclusion was that a duck's quack definitely echoes just like any other sound, but you might not notice it.
A duck''s quack really does have an echo; RETRO REPORT How we covered..
And that means you, dear reader, can decide whether the North will quack. If you have an Internet connection, go to WikiNorth and search for any northern topic that interests you.
If the North won't quack, it isn't a duck
"The quack has long been a popular and profitable subject for artists in Europe and the United States," notes John Ittmann, Curator of Prints at the Philadelphia Museum of Art.
Exhibition explores images of quacks and quackery
The conclusion was a duck's quack definitely echoes, just like any other sound -but you might not notice it.
Daisy the duck shows echo theory is plain quackers
Now, when finally finding freedom on the other side of the fence, jamaquacks have one more job: to "Quack!" as loudly as possible to their fellow jamaquacks still trapped on the inside.
More cooperative games!
Often quack products are fairly easy to spot, like the magic pills you are supposed to take to stay forever young.
Quackery ... the billion dollar miracle business
SAHIWAL -- A nine-year-old boy died after a quack allegedly administered him an expired injection in Nai Wala Bangla, Harappa city on Sunday morning.
Quack's 'expired injection' claims minor's life
PHC teams sealed 1,075 quack centres in Lahore, Faisalabad 723, Gujranwala 612 and Sheikhupura 576.
PHC teams seal 20,810 quackery outlets
The quack on the condition of anonymity demanded of the government to bound MBBS doctors to appoint compounders having at least diploma degree in relevant field.
Quacks accuse MBBS doctors of spreading HIV AIDS