This was an answer in the NYTimes crossword puzzle this week but I can’t find it in any dictionary.
Thanks.
“Sight” rhymes are words that don’t rhyme, but which end with the same letters, and therefore look (at first glance) as if they SHOULD rhyme.
Examples:
foul & soul
sour & tour
doll & roll
snow & cow
suit & quit
Examples:
love, move
cough, through
cover, over
Sight rhymes look as though they should rhyme, but when pronounced correctly they do not.
Thanks.
Is that a common word in Poetry classes, or just slang?
It’s a common term, and more widely used than just in poetry classes.
I teach Creative Writing, so I recognized the term immediately.
You were given the correct explanation.
Note: There are also some slant rhymes that used to be full rhymes, but as the centuries passed, the pronunciations of certain English words have changed; thus, they are no longer full rhymes but are instead “slant.”
(Example: “obey” and “tea” actually used to rhyme, when “tea” was pronounced “tay.”) *Just mentioning this in case in turns up in your future. 
It’s possible that this phenomenon has also occurred with a few sight rhymes, but I can’t think of any offhand.
The most memorable poem I wrote in tenth grade Creative Writing relies heavily on a sightrhyme to make the first and second lines jive.
Bubbly! Bitter! Golden! Good!
Goes well with all kinds of food.
Comes in bottles and comes in cans,
I’d drink more beer if I had more hands.
I also wrote a full 14 line sonnet of similar nature. Sadly, my poetry never reached any higher level of maturity.