Earthing

Earthing: Connecting a device to a copper rod driven into the dirt.

Types: A variety of similar items.

Working: What one does when they are not on CR4.

Principal: The person in charge of the teachers.

Load Capacity: The maximum listed working load of a wire, sling, truss, etc.

Chemical Earthing: Using listed chemicals to backfill a ground rod.

But these can all be found with a Google search.

It is very simply. Just read carefully NEC [NFPA 70] ch.250 or BS7630 or IEC60479 or DIN/VDE 0141. But better IEEE 142 [Green Book] and IEEE-80 [and other of course].

http://electricalnotes.wordpress.com/2012/09/07/difference-between-bonding-grounding-and-earthing/

A1) Look it up in Wikipedia. There's a good article on the topic in there.

A2) They're English words, though lacking in any sort of meaning through the absence of context.