About

of; concerning; in regard to:
instructions about the work; a book about the Civil War.
connected or associated with:
There was an air of mystery about him.
near; close to:
a man about my height; about six o’clock.
in or somewhere near:
He is about the house.
on every side of; around:
the railing about the excavation.
on or near (one’s person):
They lost all they had about them.
so as to be of use to:
Keep your wits about you.
on the verge or point of (usually followed by an infinitive):
about to leave.
here or there; in or on:
to wander about the old castle.
concerned with; engaged in doing:
Tell me what it’s about. Bring me the other book while you’re about it.
near in time, number, degree, etc.; approximately:
It’s about five miles from here.
nearly; almost:
Dinner is about ready.
nearby; not far off:
He is somewhere about.
on every side; in every direction; around:
Look about and see if you can find it.
halfway around; in the opposite direction:
to turn a car about.
from one place to another; in this place or that:
to move furniture about; important papers strewn about.
in rotation or succession; alternately:
Turn about is fair play.
in circumference:
a wheel two inches about.
Nautical.

onto a new tack.
onto a new course.

moving around; astir:
He was up and about while the rest of us still slept.
in existence; current; prevalent:
Chicken pox is about.
preposition
relating to; concerning; on the subject of
near or close to (in space or time)
carried on: I haven’t any money about me
on every side of; all the way around
active in or engaged in: she is about her business
about to

on the point of; intending to: she was about to jump
(with a negative) determined not to: nobody is about to miss it

adverb
approximately; near in number, time, degree, etc: about 50 years old
nearby
here and there; from place to place; in no particular direction: walk about to keep warm
all around; on every side
in or to the opposite direction: he turned about and came back
in rotation or revolution: turn and turn about
used in informal phrases to indicate understatement: I’ve had just about enough of your insults, it’s about time you stopped
(archaic) in circumference; around
adjective
(predicative) active; astir after sleep: up and about
(predicative) in existence, current, or in circulation: there aren’t many about nowadays
adv.

Old English abutan, earlier onbutan “on the outside of,” from on (see on) + be “by” (see by) + utan “outside,” from ut (see out (adv.)). By 13c. it had forced out Old English ymbe, ymbutan for meaning “in the neighborhood of.” Abouts, with adverbial genitive, still found in hereabouts, etc., probably is a northern dialectal form. About face as a military command (short for right about face) is first attested 1861, American English.

about time
about to

also see:

at about
beat about the bush
bring about
cast about
come about
do an about-face
get about
go about (one’s business)
how about (that)
just about
knock about
lay about
man about town
nose about (around)
no two ways about it
order someone about
out and about
see about
send someone about someone’s business
set about
that’s about the size of it
up and about
what about someone (something)