Dirty

From dirt + -y.

Full definition of dirty

Unclean; covered with or containing unpleasant substances such as dirt or grime.

1905, George Bernard Shaw, The author's apology from Mrs. Warren's Profession, Many persons are more comfortable when they are dirty than when they are clean; but that does not recommend dirt as a national policy.

Despite a walk in the rain, my shoes weren't too dirty.
That makes one unclean; corrupting, infecting.
Don't put that in your mouth, dear, it's dirty.
Morally unclean; obscene or indecent, especially sexually.
At the reception, Uncle Nick got drunk and told dirty jokes to the bridesmaids.
Dishonourable; violating accepted standards or rules.

2013-06-21, Oliver Burkeman, The tao of tech, The dirty secret of the internet is that all this distraction and interruption is immensely profitable....Partly, this is a result of how online advertising has traditionally worked: advertisers pay for clicks, and a click is a click, however it's obtained.

He might have scored, but it was a dirty trick that won him the penalty.
Corrupt, illegal, or improper.
I won't accept your dirty money!
Out of tune.
You need to tune that guitar, the g string sounds dirty.
Of color, discolored by impurities.
The old flag was a dirty white.
(computing) Containing data which need to be written back to a larger memory.
Occasionally it reads the sector into a dirty buffer, which means it needs to sync the dirty buffer first.
(slang) Carrying illegal drugs among one's possessions or inside of one's bloodstream.
None of y'all get into my car if you're dirty.
(informal) Used as an intensifier, especially in conjunction with "great".
He lives in a dirty great mansion.
Sleety; gusty; stormy.

M. ArnoldStorms of wind, clouds of dust, an angry, dirty sea.
Douglas Adams, So Long, and Thanks for All the FishRain type 17 was a dirty blatter battering against his windscreen so hard that it didn't make much odds whether he had his wipers on or off.

(covered with or containing dirt) filthy, soiled, sordid, unclean, unwashed; see also
(violating accepted standards or rules) cheating, foul, unsporting, unsportsmanlike
(obtained illegally or by improper means) ill-gotten
(considered morally corrupt) base, dishonest, dishonorable, filthy, despicable, lousy, mean, sordid, unethical, vile
(considered obscene or indecent) indecent, lewd, obscene, raunchy, salacious
(of color, discolored by impurities) dingy, dullish, muddied, muddy