Sentence:  <WSD>Blends</WSD>, also known as portmanteau words, are not an original part of English. That is, none occur in Old or Middle English, nor even in Elizabethan English, with the earliest known example being the rare and now obsolete term "tomaxe", a blend of "tomahawk" and "axe". 
Meaning of the word marked with <WSD> tags:  A word formed by combining two other words; a grammatical contamination, portmanteau word.