Those of you who are both English and easily offended may look away now. Everyone else, welcome. If I were childish and silly enough to pick a favourite swear word – and luckily I am, or this would be a very short post – it would have to be ‘bollocks’. It’s just one of those words you can use when really nothing else will do. It can be said with such vitriol or mirth that it makes it useful for any situation where an expletive is called for, except maybe for christenings and bar mitzvahs.
Quite different from its four-letter bedfellows, bollocks has at least four, and possibly even more, spelling variations: bollocks, ballocks, bollox and bollix. When I came to research this wonderfully fruity bit of good Old English swearing, I was quite surprised to find a huge body of work already written about it. The OED has devoted quite a bit of space to the etymology and usage of the word. Perhaps they really do prefer researching the swear words as much as schoolchildren enjoy reading them. In order to not plagiarise anyone, I will simply provide here a summary of the more common applications of the word.
As a noun: Simply yet another word for the testes (nadgers, stones or just plain old balls to you and me). Let’s put it this way, if you were playing cricket (or insert your favourite ball game here) and the ball hit you squarely in the family jewels, the last thing on your mind would be to shout “oh, my testes”. In fact, if that would be the first thing you thought to shout, seek psychiatric help immediately. Euphemisms for the word are popular too, the more famous being Jackson Pollocks, after the famous abstract expressionist, and my personal favourite (a spoonerism) Betty Swallocks. This is often shortened to simply ‘The Betties’. Confused? We have but scratched the surface (if you’ll pardon the use of the phrase).
As an interjection: “Put down your newspaper and get back to work”. “Bollocks!”
As a negation: “Was the train on time this morning?” “Was it bollocks!” The expression “That’s a load of old bollocks” is also a very popular way to use the word. Obviously, this statement intends to convey the sentiment that the previous statement is not appreciated or believed. Conversely, the “dog’s bollocks”, or simply “the bollocks” is something very good indeed, like the bees knees, or latterly (and similarly), the mutt’s nuts. This is an obvious reference to the importance of dog’s testicles to him in life. So be aware that in its shortened form, only the word the separates something wrong or bad from something truly excellent “That is just the bollocks” versus “That is just bollocks”.
As an admonition: To be told off very harshly, especially when much shouting and screaming is directed at you is called “being given a bollocking”. I don’t know why, but it really sums it up, doesn’t it?
As a transitive verb: If you have made a real mess of things, a colleague or friend may say “Well, you really bollocksed that up, didn’t you?”. This depends on how kind and caring you friends or colleagues are, I suppose.
To refer to a stupid person: Mostly used in Irish English, and usually spelled bollix, it can be used to indicate that someone is stupid, annoying, useless, or any combination thereof. “Did ye see yer man Davey on the telly last night? Jeez, what a bollix”.
As this is something I’ve wanted to write about for some time, I hope you found it to be the bollocks and not just bollocks. If you didn’t like it, maybe I dropped a bollock. Bollocks to it – I’m off.

Now where does pillock come in? As a sort of euphemistic alternative, or a diminutive of pill? My old Shorter OED is silent.
‘Pillock’ is supposedly an elongated version of ‘pill’ (an archaic expression for the penis, for the uninitiated), or a corruption of the Jutland regional word pillercock, if the big OED is to be believed.
Happily, I came across this little gem of a ditty while researching ‘pillock’:
Why did the butterfly flutter by? Because she saw the caterpillar wave his pillock at her.
=)