Blending describes a particular creative word formation process of taking at least two words, and then merging these two into a new form by deleting parts of the words, i.e. edutainment, which is made up of entertainment and education. Usually, the beginning of one and the ending of the other word are blended. Interestingly, this combining of two forms to produce a new single word not only represents a formal blending, but also a conceptual one. This is typically shown by the English word brunch, referring to a meal usually eaten late in the morning as a combination of lunch and breakfast. Accordingly, brunch is an ambiguous category – a hybrid: a brunch still has certain features of a traditional breakfast as the first meal of the day; yet, it violates certain criteria of the prototypical concept of a breakfast as a meal eaten early in the morning.
Similarly, workaholic represents a further conceptual and formal blending to describe someone addicted to his work. Here, the conceptual blending is one between the notion of being addicted, which is commonly associated with alcohol, and the so-called target area of a person’s addiction, i.e. work.
"'Well, "slithy" means "lithe and slimy". "Lithe" is the same as "active". You see it's like a portmanteau -- there are two meanings packed up into one word.' "
Lewis Carroll’s Jabberwocky
A sub-category of blends is presented by portmanteau words. The term was first introduced by Lewis Carroll to describe many of his unusual words to be found particular in his poem Jabberwocky.
Like a blend, a portmanteau is composed of parts of two (or even more) words, e.g. in the classic example smog. In this combination of two root morphemes, as in portmanteau words in general, it appears rather difficult to distinctively assign certain sounds to the source words. Does the -o- belong to smoke or to fog? Thus, strictly linguistically speaking, the notion of the portmanteau is used to describe those cases in language, in which a single morph in one word at the same time represents at least two grammatical elements, such as in the French "du" or Lewis Carrol's "slithy" which contains both "lithe and slimy".