clean (adj.)

Old English clæne "free from dirt or filth, unmixed with foreign or extraneous matter; morally pure, chaste, innocent; open, in the open," of beasts, "not forbidden by ceremonial law to eat," from West Germanic *klainja- "clear, pure" (source also of Old Saxon kleni "dainty, delicate," Old Frisian klene "small," Old High German kleini "delicate, fine, small," German klein "small;" English preserves the original Germanic sense), perhaps from PIE root *gel- "bright, gleaming" (source also of Greek glene "eyeball," Old Irish gel "bright"). But Boutkan doubts the IE etymology and that the "clean" word and the "small" word are the same.

"Largely replaced by clear, pure in the higher senses" [Weekley], but as a verb (mid-15c.) it has largely usurped what once belonged to cleanse. Meaning "whole, entire" is from c. 1300 (clean sweep in the figurative sense is from 1821). Sense of "not lewd" (as in good, clean fun) is from 1867; that of "not carrying anything forbidden" is from 1938; that of "free of drug addiction" is from 1950s. To come clean "confess" is from 1919, American English.

clean (v.)

mid-15c., "make clean," from clean (adj.). Related: Cleaned; cleaning. From clean out "clean by emptying" comes sense of "to leave bare" (1844); cleaned-out "left penniless by losses" is from 1812.

clean (adv.)

Old English clæne "dirtlessly," also "clearly, fully, entirely;" see clean (adj.). Compare similar use of German rein "clean."

Definitions of clean
clean (adj.)
free from dirt or impurities; or having clean habits;
cats are clean animals
clean dishes
children with clean shining faces
clean white shirts
a spotlessly clean house
clean (adj.)
free of restrictions or qualifications;
a clean bill of health
Synonyms: clear
clean (adj.)
(of sound or color) free from anything that dulls or dims;
efforts to obtain a clean bass in orchestral recordings
Synonyms: clear / light / unclouded
clean (adj.)
free from impurities;
clean water
Synonyms: fresh
clean (adj.)
(of a record) having no marks of discredit or offense;
a clean voting record
a clean driver's license
clean (adj.)
ritually clean or pure;
clean (adj.)
not spreading pollution or contamination; especially radioactive contamination;
the tactical bomb is reasonably clean
a clean fuel
Synonyms: uncontaminating
clean (adj.)
(of behavior or especially language) free from objectionable elements; fit for all observers;
good clean fun
a clean joke
Synonyms: unobjectionable
clean (adj.)
free from sepsis or infection;
a clean (or uninfected) wound
Synonyms: uninfected
clean (adj.)
morally pure;
led a clean life
Synonyms: clean-living
clean (adj.)
(of a manuscript) having few alterations or corrections;
a clean manuscript
Synonyms: fair
clean (adj.)
(of a surface) not written or printed on;
a clean page
Synonyms: blank / white
clean (adj.)
exhibiting or calling for sportsmanship or fair play;
a clean fight
clean (adj.)
without difficulties or problems;
a clean test flight
clean (adj.)
thorough and without qualification;
a clean break
a clean getaway
a clean sweep
clean (adj.)
not carrying concealed weapons;
clean (adj.)
free from clumsiness; precisely or deftly executed;
a clean throw
he landed a clean left on his opponent's cheek
Synonyms: neat
clean (adj.)
free of drugs;
after a long dependency on heroin she has been clean for 4 years
clean (v.)
make clean by removing dirt, filth, or unwanted substances from;
The dentist cleaned my teeth
Synonyms: make clean
clean (v.)
remove unwanted substances from, such as feathers or pits;
Synonyms: pick
clean (v.)
clean and tidy up the house;
Synonyms: houseclean / clean house
clean (v.)
clean one's body or parts thereof, as by washing;
clean up before you see your grandparents
clean your fingernails before dinner
Synonyms: cleanse
clean (v.)
be cleanable;
This stove cleans easily
clean (v.)
deprive wholly of money in a gambling game, robbery, etc.;
The other players cleaned him completely
clean (v.)
remove all contents or possession from, or empty completely;
The boys cleaned the sandwich platters
The trees were cleaned of apples by the storm
Synonyms: strip
clean (v.)
remove while making clean;
clean (v.)
remove unwanted substances from;
Synonyms: scavenge
clean (v.)
remove shells or husks from;
clean grain before milling it
clean (adv.)
completely; used as intensifiers;
clean forgot the appointment
Synonyms: plumb / plum
clean (adv.)
in conformity with the rules or laws and without fraud or cheating;
Synonyms: fairly / fair
clean (n.)
a weightlift in which the barbell is lifted to shoulder height and then jerked overhead;
Synonyms: clean and jerk