What is a near rhyme?
A near rhyme (also called slant rhyme or partial rhyme) is a rhyme scheme in which the words in question don't completely rhyme, but parts of them do, like in a syllable or two (as in "gullible" and "eligible"), or the words may sounds similar, but not exactly the same (such as "soul" and "all").
There is only one true rhyme for vanished: banished. A true rhyme is a word that is exactly the same except for whatever is before the first vowel. In this case, the first vowel is "a" (vanished; banished). There is also one near rhyme: famished. A near rhyme is a word that is exactly the same except for one sound (vanished and famished). There are no other rhymes for vanished, exact or near.
Slant rhyme is sometimes called half rhyme, imperfect rhyme, near-rhyme, oblique rhyme, or lazy rhyme, and it consists of words that sound almost similar. Often, either, in stressed syllables, the vowel sounds the same but the consonant sounds do not, or vice versa. In stanza #3: curtain/repeating In stanza #4: longer/implore