Drilled

Drilled is the past participle of drill and functions as both a verb form and an adjective. As an adjective, it describes something that has been bored or perforated by a drill or similar tool. The term is used across disciplines to indicate a hole or bore produced by drilling. In engineering and manufacturing, drilled features are common: drilled holes in metal, wood, or composites; drilled holes for fasteners, pins, or wiring; and drilled cores and samples in material testing. In energy and mining, the process of drilling is used to create wells or extract cores; drilled wells are common in oil, gas, and groundwater exploration, while rock cores are obtained from boreholes for analysis.

In dentistry and medicine, drilling is a preparatory step: a tooth may be drilled to remove decay, and surgical drilling is used to access bone or create channels for implants and instrumentation.

In training and education, drill is used to describe repetitive practice to embed procedures or responses. People may be described as drilled in safety protocols, or phrases like drilled into memory are used to express thorough memorization through repetition.

Drilled also appears in cultural contexts as a title for various works; the meaning depends on the work. The term is closely related to drill and drilling, and it has specialized technical senses in geology and archaeology (core drilling).