treyf is the hebrew word for 'unclean'--pork is treyf, and so are insects (and insects of the sea--any sea animal with an ecto skeleton) -locust are an exception.. and having a tree and insect with the same name--it might be that the fruit of the tree is really what is being talked about --but i don't know of any vegetable products, from the ground or trees, that aren't kosher--so why locust tree's would be mentioned is kind of strange.

some foods are not considered kosher for passover--(and some like chocolate are accepted by some groups, and rejected by others as being acceptable foods for passover!)

kosher basicaly means clean-- foods are kosher, and so are kitchens and utensils and other things..(or they are made kosher by real and ritual cleaning!) glatt kosher is kosher to the extreme-

here in north east (and in NY in particular) many hebrew and yidish words are part of the lexis.