Mod con and Whatsit

Mod con noun - Something that adds to one's ease of living.

Whatsit and mod con are semantically related. In some cases you can use "Whatsit" instead a noun phrase "Mod con".

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

Mod con and whatsit are semantically related. Sometimes you can use "Mod con" instead a noun "Whatsit".