1 clean /ˈkliːn/ adjective
cleaner; cleanest
1 clean
cleaner; cleanest
Learner's definition of CLEAN
: free from dirt, marks, etc. : not dirty
: tending to keep clean
: free from pollution or other dangerous substances
: not causing pollution
: not yet used
of a document : not having any mistakes
: pleasingly simple
: having edges that are straight and smooth
: completely and quickly done
sports : done in a skillful and impressive way without mistakes or awkwardness
: not showing evidence of any broken rules or laws see also clean slate (below)
: not connected with or involving anything illegal or morally wrong
: not referring to anything sexual or offensive
not used before a noun : no longer using drugs : not addicted to drugs
not used before a noun, informal : not carrying any weapons, drugs, etc.

clean as a whistle

see 1whistle

clean slate

also British clean sheet
: a person's record (as from a school or a job) that shows no evidence of any problems, broken rules, etc. : a clean record
clean sheet British : a game in which the opposing team is prevented from scoring

clean sweep

: a victory in which one side or team wins every game, contest, etc.
: a complete change in something

come clean

: to tell the truth about what happened : to stop hiding the truth

give (someone or something) a clean bill of health

see 1bill

keep your nose clean

see 1nose

make a clean breast of

see 1breast

wipe the slate clean

see 1wipe

— cleanness

/ˈkliːnnəs/ noun [noncount]
2 clean /ˈkliːn/ verb
cleans; cleaned; cleaning
2 clean
cleans; cleaned; cleaning
Learner's definition of CLEAN
: to make (something) clean : to remove dirt, marks, etc., from (something)
[+ object]
[no object]
see also clean up 1a (below)
[no object] : to become clean
[+ object] : to make (something, such as a room) neat and orderly see also clean out 1 (below), clean up 1b (below)
[+ object] : to remove the organs from the inside of (an animal) before cooking

clean house

see 1house

clean out

[phrasal verb]
clean (something) out or clean out (something) : to remove unwanted things from (a room, closet, etc.)
clean (someone or something) out or clean out (someone or something) informal : to steal or take everything from (someone or something)
clean (someone) out or clean out (someone) informal : to use up all or most of someone's money

clean up

[phrasal verb]
clean (something) up or clean up (something)
: to remove (dirt, spilled substances, etc.)
or clean up : to make (a room or space) clean and orderly
◊ To clean up after someone is to make a place clean after someone has made it dirty or messy.
: to remove pollution from (something) see also cleanup
clean up or clean (yourself) up : to make yourself clean : to wash your face and hands
clean (something) up or clean up (something)
: to remove whatever is illegal or immoral from (something)
: to make (something) clearer or more acceptable
clean (something) up or clean up (something) informal : to eat all of (something)
informal : to make a large amount of money
clean up your act informal : to behave in a way that is more acceptable

clean your plate

: to eat all the food on your plate
Usage see: cleanse
3 clean /ˈkliːn/ adverb
3 clean
Learner's definition of CLEAN
: all the way : completely or entirely
4 clean /ˈkliːn/ noun
4 clean
Learner's definition of CLEAN
[singular] informal
: an act of removing dirt from something