A smell-a-like is a perfume that smells like a designer fragrance but with a different name and packaging, and at a cheaper price. A smell-a-like isn't an exact copy, but often smells very similar.
I bought a bottle of marks and spencers black amber and a bottle of chanel coco noir on the same day and they smell exactly the same.
the chanel is stronger. But comparing prices the marks and spencers version is a brilliant price at £18.00 and the chanel at £165.00. If you did a close eyes test you wouldn't know which one was which.