Originally a typo of the commonly used emoticon <3, <4 is now used to convey a love so great that <3 simply cannot explain it.

A jack off buddy (from 'cum' /'come', meaning 'semen', and 'companion'); a friend that you get together with for sessions of solo or mutual masturbation
Variant of: cumpanion (from 'companion' & 'cum'); jack off buddy & wank bud & JO buddy
Similar to: fuck buddy

The <4 is similar to the <3. It is just a heart with a little more meaning to it. The 4 stands for 4 ever/ forever.

The broheart. Used to express a deep affection for a bro, with absolutely no homosexual intent.

A symbol used when someone uses a 4 instead of a 3 when making a heart symbol <3. This can be done on accident making the user look stupid or it can be done on porpose meaning the user more than <3's them.

A sign showing you are meant for each other :)

an uncommon mis-spell of “<3”, yet still shows your mega appreciation for a person you uwu ^~^ over.