Nothing! Don't try to analyse everyday phrases like this word for word - this approach doesn't work. You can't break this question down into separate words - you have to accept the whole expression as it is and understand the global meaning:
"What + verb be + X + like" ? = Describe X / Tell me about X
So "What is the weather like?" means "Tell me about the weather. Is it hot/cold/sunny/rainy?"
Accept it, learn it and practise it - that's the only way. Trying find a meaning for each word in isolation or - worse still - trying to translate every word is a waste of time.