【Counterfeit】 , 【spurious】 , 【bogus】 , 【fake】 , 【sham】 ,  【pseudo】 , 【pinchbeck】 , 【phony】 are comparable when meaning not at all what it is said to be or purports to be.

【Counterfeit】  implies that what is so qualified is an imitation of something else and usually of something finer, rarer, or more valuable and that the imitation is intended to deceive or defraud; thus, play money intended for the use of children at play is imitation but not 【counterfeit】 money; a clipped coin, though intended to defraud, is a real coin and not 【counterfeit】 ; but a false banknote is both imitation and intended to deceive or defraud and is 【counterfeit】 .

【Spurious】 designates something as false rather than true or genuine; it carries no strong implication of being an imitation; thus, a 【spurious】 painting is one that is falsely attributed to a well-known painter; 【spurious】  writings attributed to Shakespeare are those thrown out of a canon of his work; a 【spurious】 condition is one which only superficially resembles the genuine condition.

The word does not necessarily connote a fraudulent purpose; it may suggest an honest mistake, confusion, or lack of scholarship.

【Bogus】 carries the implications of fraudulence or deceit and applies to whatever may be passed off on one or may attempt to deceive one as to its true nature.

【Fake】 and  【sham】 are often equal to the past participial adjectives faked and shammed, both usually implying a more or less obvious imitation of something real.

But 【fake】 emphasizes the idea of a false fabrication or of fraudulent manipulation and 【sham】 stresses the thinness and obviousness of the disguise, the naïveté of the deception, or often the lack of intent to imitate exactly.

【Pseudo】 actually means false in any way; as an adjective modifying a noun or in the combining form joined with a separate noun it frequently implies pretense rather than fraud or spuriousness rather than counterfeiting.

【Pinchbeck】 implies a cheap, tawdry, or worthless imitation often of something precious, costly, or grand; it rarely implies an intent to deceive and is therefore closer to 【sham】 than to 【counterfeit】 .

【Phony】 stigmatizes something which does not impose but puzzles or perplexes since it has a dubious appearance of reality.

【Imposture】 , 【cheat】 ,  【fraud】 ,  【sham】 ,  【fake】 ,  【humbug】 ,  【deceit】 ,  【deception】 ,  【counterfeit】  all mean something which pretends to be one thing in its nature, character, or quality but is really another.

【Imposture】 applies not only to an object but to an act or practice which is passed off to another as genuine, authentic, or bona fide.

【Cheat】 applies chiefly to something or sometimes to someone that wins one’s belief in its or his genuineness, either because one is deliberately misled or imposed upon by another or is the victim of illusion or delusion.

【Fraud】 applies to a deliberate, often criminal, perversion of the truth. Applied to a person it may be less condemnatory and suggest pretense and hypocrisy.

【Sham】 applies to a close copy of a thing, especially to one that is more or less obviously a fraudulent imitation.

【Fake】  applies either to a person that represents himself as someone he is not or, more often, to a worthless thing that is represented as being something that it is not;  【fake】  differs from  【fraud】  in not necessarily implying dishonesty in these representations, for a  【fake】 may be a joke or a theatrical device, or it may be a clear 【fraud】 .

【Humbug】 applies to a person or sometimes a thing that pretends or is pretended to be other and usually more important than he or it is, not necessarily because of a desire on the part of the person involved to deceive others but often because he is self-deceived.

【Deceit】  and  【deception】  both apply to something that misleads one or deludes one into taking it for what it is not.

【Deceit】 , however, usually suggests the work of a deceiver or of one that misleads or leads astray.

【Deception】 , on the other hand, often suggests a quality or character in the thing which causes one to mistake it or frankly to take it as other than it really is.

【Counterfeit】 applies to a close imitation or copy of a thing (as a coin, a banknote, or a bond) that depends upon pictorial devices or engraved designs for assurance of its genuineness; the term usually also implies the passing or circulation of such an imitation as if it were genuine. The term is also applicable to a thing or, less often, to a person that passes for something other than it actually or truly is.