portmanteau word

noun1

1. •
   A word which combines the meaning of two words (or, rarely, more than two words), formed by combining the words, usually, but not always, by adjoining the first part of one word and the last part of the other, the adjoining parts often having a common vowel.

   • 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. — 1871