Used in an app called 'Vent' for smartphones, it means "Here for You" where the for is '4.'
Person 1 - "oh no i feel so alone"
Person 2 - "H4U"

(I do not reccomend using this in real life speech)
by MaxKFuller October 18, 2015
Get the H4U mug.
It is another way to say "here for you/I am here for you"
Person 1: I feel miserable

Person 2: u knw im H4U <3
by bjoy October 19, 2015
Get the H4U mug.
raven: i am miserable
vent: h4u
by ravenoodles October 14, 2015
Get the H4U mug.