Grounding hump – A feature of an electrical junction box where the grounding hole is on a inwardly curved hump so that the grounding nut will not protrude beyond the box.
Grail [item] – An extremely hard-to-find object that you are forever looking for but unlikely to ever find. E.g. a grail tool, or book, or game.
Zenithal priming – A painting technique that creates pre-shading by priming the object (e.g. a gaming miniature) in one color and then spray painting from the top (zenith) with a lighter color (usually white or light gray) to create a top-down underlight that will show through subsequent thin basecoats.