Wiktionary
lose weight
vb. (context intransitive English) to become less heavy.
WordNet
Usage examples of "lose weight".
His appetite had never really returned, and he continued to lose weight.
But in the summer he developed a hacking cough and began to lose weight.
Even by pulling out all the fiction titles and the stuff on how to become a millionaire or lose weight, there are far too many books of value to save.
As the car slowed, he began to lose weight, and his gorge began to rise in an exact correspondence.