Welcome to some more British slang. Many of these expressions are also used in Australia.
Daft - My Dad used to call me a daft 'apeth which is short for a daft half penny (in old money). It basically means stupid.
Dekko - To have a look at something.
Dear - If something is dear it means it is expensive. I thought Texan insurance was dear.
Dicky - Dicky rhymes with sicky and means you feel sick.
Diddle - To rip someone off or to con someone is to diddle them. When you visit England, check your change to make sure you haven't been diddled!
Dim - A dim person is stupid or thick or a dimwit. Dimwit - Someone a bit on the dim side.
Dishy - If someone is a bit of a dish or a bit dishy it means they are attractive or good looking.
DIY - This is short for do it yourself and applies not just to the DIY stores but also to anything that you need to do yourself. For example, if we get really bad service in a restaurant (oh, you noticed!) then we might ask the waiter if it is a DIY restaurant - just to wind them up.
Do - A party. You would go to a do if you were going to a party in the UK.
Do - If you go into a shop and say "do you do batteries?" it means "do you sell batteries".
Do - If you drive along a motorway in the wrong lane the police will do you. You could then tell your friends that you have been done by the police. Prosecute is another word for it!
Doddle - Something that is a doddle is a cinch, it's easy. Unlike ordering water in Texas with an English accent, which is definitely not a doddle!
Dodgy - If someone or something is a bit dodgy, it is not to be trusted. Dodgy food should be thrown away at home, or sent back in a restaurant. Dodgy people are best avoided. You never know what they are up to. Dodgy goods may have been nicked. When visiting Miami I was advised by some English chums that certain areas were a bit dodgy and should be avoided!
Dog's bollocks - You would say that something really fantastic was the dog's bollocks. Comes from the fact that a dog's bollocks are so fantastic that he can't stop licking them! Nice huh? Often shortened to just "The dog's".
Dog's dinner - If you make a real mess of something it might be described as a real dog's dinner. A bit like some joint Anglo-American approaches to Eastern Europe for example!
Donkey's years - Someone said to me the other day that they hadn't seen me for donkey's years. It means they hadn't seen me for ages.
Drop a clanger - When I asked a large lady on the tube if she would like my seat since she was so obviously pregnant, she took the seat then told me she was fat, not pregnant! Boy did I drop a clanger. You might make a gaffe. Either way it was horrendously embarrassing, especially as half the people on the tube had heard me!
Duck - In and around Leeds you will find older people might call you "duck" in the same way that they might call you "love" or "dear" in other places. Usually pronounced more like "dook", which rhymes with "book".
Duff - Anything that is duff is useless, junk, trash. It usually means that the object doesn't do the job it was intended for. Our last Prime Minister was pretty duff!
Duffer - Any person that is duff could be referred to as a duffer. The Prime Minister was a duffer.
Dull - You would say something that was no longer sharp was dull. We would say blunt. To us something is dull if it is boring. It can apply to things - like a film could be dull. It also applies to people - I can think of several people who are dull!
Clancy's comment: Well, there ya go, Cobber. Ope ya loved these little blighters.