Things and Whatsit

Things noun - Any movable possession (especially articles of clothing).

Whatsit and things are semantically related. In some cases you can use "Whatsit" instead a noun "Things".

Whatsit noun - A small article the actual name of which one either does not know or cannot remember.

Things and whatsit are semantically related. Sometimes you can replace term "Things" with "Whatsit", this nouns are similar.