Google satya and you will find lots of Indian restaurants and a movie. If you include truthfullness in your search, you will come closer to the meaning of the second yama. Satya is the sanskrit word for truth. The practise of satya goes way beyond not lying. It includes being truthful and honest with ourselves, followed by being truthful with anyone else.
It does not mean that you have to say out loud all harmful thoughts appearing in your mind. Saying: “What a ugly dress are you wearing today”, while your neighbour passes by, is not satya. This action would interfere with the first yama ahimsa, non-harming. If you can not say anything nice, do not say it all. Moreover your mind and the resulting thoughts are not The Truth. Though, at times you have to confrontate others with their behaviour. For example your brother is addicted to alcohol and this affects the whole family in a negative way. While dealing with difficult situations like these, it is good to remember the first yama: non-violence and try to handle with love.
Forcing yourself in an intense yoga practise, because your mind says you have to while you are not feeling well, is an example of not practising satya and/or ahimsa. If I find it difficult to be truthful I remind myself that every time I am being untruthful to myself, I install an internal block which keeps me from seeing my own divine radiance. In addition, the law of Karma will grab you anyway. Most of us have experienced that at least one time during their life. If you break that beautiful vase of your grandma and you do not dare to tell her, she will find out anyway and you will feel even worse for not telling her straightaway.
Practising satya will result in openness towards yourself and others. And the best part, it just feels great to be honest, to speak The Truth, to listen to The Truth, to live The Truth. It will bring your relationships with others to a higher level. And at last but not the least, I can assure you, it will increase your feelings of happiness.