Hi, I know how you feel and I am sure other parents will come over and chat to you about their experience. I have two boys and the first one spoke absolutely fine and his language developed well, vocab and pronounciation.
First, I don't think it 'means' anything. It doesn't mean that you haven't spoken to him enough, or that he's watched too much telly, or that he's had a dummy. Some children develop other skills before they start speaking, and it's well within the 'normal' range.
Some other parents will probably say that their child started speaking later, but in full sentences, and that your child will catch up soon. That is true in many situations, but not all.
There are lots of resources online to help you understand how language develop and how to help your child's language skills develop but the fact is, there are no magic potion.
One book that I really liked is 'It Takes Two to Talk'. It's quite expensive but you can get it from library. If they don't have it you can ask them to order it for a fee. It's very helpful.
One trick that was given to me ages a go is to try and spend 10-15 minutes a day one-to-one, with no distraction, music, radio etc, and sit down on the floor and 'comment' on your child's play. It's hard as you will feel that it is a monologue.
Also, it's important to speak in very short sentences, three words, and repeat a key word. 'Want Milk? Milk? MMMM... Cold Milk' etc. I know it sounds very silly, but it's much easier for a child to process that information and repeat it rather than saying 'would you like a class of milk?' I hope that makes sense...
Encourage him to make sounds - airplane sounds, car sounds, animal noises. Very simple and easy one syllable sound.
Don't ask 'please say MILK. Say MILK'. Just give your child the time to answer.
Have you tried signing a few words? There are lots of resources online for Makaton signs. It might help him to not get frustrated if you can uderstand him. Some key words that I used loads is 'all gone, more, milk, finish, go'.
A nice game to play is to blow bubbles, and say 'Ready Stready.... GO' and the second time, give your child the time to try and say GO. Praise him for any sounds that he makes.
Another tip (sorry this has to be the longest message ever) try to repeat sounds that he makes. Any sound, either grunting, babbling sounds, anything. It's a very simple way to tell him that you are listening to him.
Website that I like www.ican.org.uk , and www.talkingpoint.org.uk.
One last thing, have you had his hearing tested? It might be worth talking to your GP about this just to be sure that his hearing is ok.