GWD: Thingamajig

It hardly even needs to be said, as it's a synonym of "Whatchamacallit" but then again, saying things that needn't be said is so fucking gnomish, that I'm going to say it, anyway...

thing·am·a·jig

Variant(s): or thing·um·a·jig \ˈthiŋ-ə-mə-ˌjig\

Function: noun

Etymology: alteration of earlier thingum, from thing

Date: 1828

: something that is hard to classify or whose name is unknown or forgotten

And I'll add that what this word means is quintessentially gnomish -- a word to classify something that is hard to classify.

I'll throw in thingamabob in as well, as a synonym of "thingamajig."

thing·am·a·bob

Pronunciation: \ˈthiŋ-ə-mə-ˌbäb\

Function: noun

Date: 1750

You can see the nature of gnomish language already. When we're through, here, you'll have a keen sense of gnomish syntax. Interesting that "thingamabob" predates "thingamajig" -- clearly, gnomish language evolved a bit in that span of time, but pointless innovation is key to gnomish life.