portmanteau word, n.
a new word formed by joining two others and combining their meanings
<noun.communication>
blend portmanteau portmanteau word
sample sentences
"`smog' is a blend of `smoke' and `fog'""`motel' is a portmanteau word made by combining `motor' and `hotel'"
"`brunch' is a well-known portmanteau"
semantic pointers
member of this domain (usage)
hypernym