Webster's Revised Unabridged Dictionary · 1913

Sip

Sip (sip) , transitive verb

[Old English sippen; akin to OD. sippen, and Anglo-Saxon s{not transcribed}pan to sip, suck up, drink. See Sup, transitive verb]

1.
To drink or imbibe in small quantities; especially, to take in with the lips in small quantities, as a liquid; as, to sip tea.
Every herb that sips the dew. — Milton
2.
To draw into the mouth; to suck up; as, a bee sips nectar from the flowers.
3.
To taste the liquor of; to drink out of. [Poetic]
They skim the floods, and sip the purple flowers. — Dryden

Sip , intransitive verb

To drink a small quantity; to take a fluid with the lips; to take a sip or sips of something.
[She] raised it to her mouth with sober grace; Then, sipping, offered to the next in place. — Dryden

Sip , noun

1.
The act of sipping; the taking of a liquid with the lips.
2.
A small draught taken with the lips; a slight taste.
One sip of this Will bathe the drooping spirits in delight Beyond the bliss of dreams. — Milton
A sip is all that the public ever care to take from reservoirs of abstract philosophy. — De Quincey