Here's how we can approach understanding it:
Possible Interpretations:
* Construction:
* Unfinished Sill: It might refer to a sill that is in the initial stage of construction, meaning it lacks final finishes like paint or sealant.
* Rough-Cut Sill: A sill made from rough-cut lumber, which means it's unplaned and has a more natural, rustic appearance.
* Subfloor Sill: A sill that forms part of the subfloor system, often made from wood or concrete.
* Geology:
* Unpolished Sill: In geology, a sill is a tabular igneous intrusion that has intruded between existing rock layers. "Rough" could refer to a sill that hasn't been polished or smoothed for study or display.
To get a clearer definition, you'll need more context.
For instance, please tell me:
* Where did you encounter the term "rough sill"? (e.g., a book, a construction project, a geological report)
* What is the surrounding context? (e.g., what was being discussed or what was the topic of the text?)
With more information, I can provide a more specific and accurate definition of "rough sill."