Green’s Dictionary of Slang

fuck, the phr.

also fuck, t.f.

1. [1910s+] (also in the fuck, in the eff) var. on hell, the phr. (1) used in questions, e.g. what the fuck...? phr.

2. [1950s+] as infix, e.g. shut the fuck up.

3. [20C+] a general intensifier implying quantity or intensity; a var. on hell, the phr. (3)

4. [1970s+] a general intensifier used to express anger, annoyance, impatience; a var. on hell, the phr. (2)

5. [1970s+] the essence, the spirit, ‘the daylights’, e.g. slap the fuck out of.

6. [1980s+] abbr. of what the fuck...? phr. (1) or vars.; the question word is implied.

In phrases

get the fuck out (v.)

[1940s+] to leave, to go away; the use of fuck intensifies the urgency.

kick (the) fuck out of (v.)

[1970s+] to beat someone up severely.

scare the fuck out of (v.)

[1990s+] to terrify.

In exclamations

get the fuck out! [1950s+]

1. an intensified var. on go away!

2. an intensified var. on get out of here! and similar phr. of (joc.) disbelief.