A portmanteau is essentially a word formed by a combination of other words. Most portmanteau words are formed by a blend of two words, but some may have more. Words such as brunch (a combination of "breakfast" and "lunch") are pretty obvious, but there are some that are not quite as easy to decipher.
In this gallery, we compile some of the words you might not realize are portmanteaus. Click on and see how many you can recognize.