What is another word for under thing?
Pronunciation: [ˌʌndə θˈɪŋ] (IPA) 
The phrase "under thing" can be a bit vague, but there are plenty of synonyms to choose from depending on the context. For example, "undergarment" could be used to refer specifically to underwear. "Base layer" or "under layer" might be used when talking about clothing worn underneath outerwear. "Foundation" or "base" could refer to the underpinnings of a structure or project. In a similar vein, "groundwork" or "preliminary step" could refer to the initial stages of something. And if you're looking for a synonym that's a bit more whimsical, "underbelly" or "beneath the surface" could be used to describe hidden or secret aspects of a situation.
