What is the term for when a word begins with the previous word's ending sound?
Solution 1:
The term is called haplology. Where one sound is omitted and the words are pronounced together. Newspaper route becomes newspaperout, for example. Often times haplology refers to repeated sounds within a single word, but in English (and possibly some other languages) it happens with multiple words.
Solution 2:
Assonance is the closest word I know of. Generally, it describes words that have repeated vowel sounds but don't rhyme. For example, "fold" and "own". It could be used generically to mean what you're asking, but it wouldn't specifically mean that. And it is more correct to use assonance to describe words where the repeated sounds are in the same place, but it is a better bet than alliteration or rhyme. Consonance means the same thing for consonant sounds.