Oxford Advanced American Dictionary

Definition of here adverb from the Oxford Advanced Learner's Dictionary

Oxford3000

here

adverb
here pronunciation English hɪə(r) here pronunciation American hɪr
 
1 used after a verb or preposition to mean ‘in, at or to this position or place’I live here.Put the box here.Let's get out of here.Come over here.2 now; at this pointThe countdown to Christmas starts here.Here the speaker paused to have a drink.3 used when you are giving or showing something to somebodyHere's the money I promised you.Here's a dish that is simple and quick to make.Here is your opportunity.Here comes the bus.I can't find my keys. Oh, here they are.Here we are (= we've arrived).4 here to do something used to show your role in a situationI'm here to help you.5 (used after a noun, for emphasis)My friend here saw it happen.
Idioms

by here

(Welsh English) here; to hereCome by here now!

here and there

in various places
Papers were scattered here and there on the floor.

here goes

(informal) used when you are telling people that you are just going to do something exciting, dangerous, etc.‘Here goes,’ said Grace and took a deep breath.

here's to somebody/something

used to wish somebody health or success, as you lift a glass and drink a toast
Here's to your future happiness!

here, there and everywhere

in many different places; all around

here we go

(informal) said when something is starting to happen‘Here we go,’ thought Fred, ‘she's sure to say something.’

here we go again

(informal) said when something is starting to happen again, especially something bad

here you are

(informal) used when you are giving something to somebodyHere you are. This is what you were asking for.

here you go

(informal) used when you are giving something to somebodyHere you go. Four copies, is that right?

neither here nor there

not important
Synonym
irrelevant
What might have happened is neither here nor there.
more at out of here at out adverb preposition