Do you mean:
When YOU meet A lazy student ....
Capitals and articles and YOU not U!
There are other mistakes there... but U (for YOU) is definitely lazy, bad English.
I always tell students not to be lazy like this. But I can not make them do their homework if they don't want to, or simply don't have the time.
What I can do is give them little tiny bits of work to do: a song to listen to; a small grammar game they can play online; etcetera. If it is very little effort and only takes ten minutes they might actually do it. A little is better than nothing.
But basically, it's down to the student. (it's the student's responsibility)
If there is no homework to mark... I can have a little nap instead! And that's ME being lazy!