wake up Definition

wake¹
verb woke, woken, waking

tr & intr
1a. To rouse or be roused from sleep;

Thesaurus: arise, awaken, get up, rouse, stir, rise and shine; Antonym: sleep.
Form: wake someone up (also)
Form: wake up
tr & intr
1b. To stir or be stirred out of a state of inactivity or lethargy, etc.

Thesaurus: stimulate, provoke, enliven, galvanize.
Form: wake someone up (also)
Form: wake up
intr
2. To stay awake at night; to keep watch or stay vigilant.
3. To disturb (eg a night or silence, etc) with noise.

noun

1. A watch or vigil kept beside a corpse.
2. dialect
An annual holiday.
3. historical
The feast of the dedication of a church, formerly kept by watching all night.

Derivative: waking
noun, adj

Etymology: Anglo-Saxon wacan to become awake, and wacian to stay awake.

Phrasal Verb: wake up or wake someone up to something

To become or make them aware of (a fact, circumstance or situation, etc).

Info:

These four verbs are virtually synonymous, with wake the most commonly used. All can be used with or without an object; all can be used both in the literal sense ‘to rouse from sleep' and in the figurative sense ‘to arouse or provoke (feelings)'. The only difference between them is that awake and awaken are never followed by up.