Reach, or reaching is a synonym for come, coming, arrive, arriving, attend, attending etc.
It is often used in place of such phrases as: "Are you coming?", "Are you going\going to make it?", " Are you on your way?" in the interrogitive, and "Come over", "I'll be there", "I'm on the way" etc. in the exclamatory.
It often stands alone as the sole word in an (sms)text message.
Anecdotal evidence could lead one to believe that this unconventional, ambiguous usage of the word was introduced into the urban lexicon by homophobic, adolescent, or twenty-something wiggas, who possibly feared reprisal at the double entendre the words come and coming conjured in their cohorts, friends and\or homies.
Ultimately, and this is just a gut feeling, I believe the aforementioned (admittedly dubious) etymological origin storysmacks of the clumsy and often extremely loose and liberal repurposing of words and phrases which have become commonplace in the post-www.\sms era of of the past few decades.
Said slanglish was probably first uttered by one young hip-hop sycophant to a friend, or acquaintance who probably had to ask for clarification as to its contextual meaning. Apparently, it was deemed either sufficiently cool and\or enough of a time\140 character saver when used as a single word in place of an entire sentence, that it managed to gain traction and be thusly co-opted and amalgamated into the lols and imhos of females aged 12-32...ensuring it's inclusion in the Urban Dictionary.
the slang βreachingβ can be used in a couple of ways. youβre able to use it when someoneβs over exaggerating something to make it seem worse than what it actually was, or taking something too far.
-example 1, over exaggerating-
person 1: *accidentally bumps into somebody*
person 2: hey !
person 1: oh, iβm sorry !
person 3: what happened?
person 2: they hit me on purpose, and they also insulted me for no reason ! *cries*
person 1: you reaching, fool...
-example 2, taking it too far-
*two students roasting each other for fun*
person 1: and thatβs why you balding at the age of 16.
person 2: oh yeah? well thatβs why your parents left you, and told you straight up, that youβre a waste of oxygen and space. it all makes sense why youβre so disrespectful towards everybody knowing that you got family issues, i mean... itβs not like you have a family.
everybody: *silence*
person 3: yo, you reaching...
person 1: *cries in orphan*