back
Definition of back:
part of speech: adjective
That is situated behind; previous.
part of speech: noun
A brewers vat or large open tub for containing beer; a ferry- boat.
part of speech: adverb
To the place from whence one came; to a former state or condition; behind; not advancing again.
part of speech: noun
The upper part in animals, and the hinder part in man; the rear; the part out of sight; a miners term for joints; that part of a mineral lode nearest the surface.