If you refer to words or pictures that are related to sex as smut, you disapprove of them because you think they are rude and unpleasant and have been said or published just to shock or excite people.
[disapproval]
I find the media's growing obsession with smut and sensation deplorable.
...schoolboy smut.
2. uncountable noun
Smut or smuts is dirt such as soot which makes a dirty mark on something.
smut in British English
(smʌt)
noun
1.
a small dark smudge or stain, esp one caused by soot
2.
a speck of soot or dirt
3.
something obscene or indecent
4.
a.
any of various fungal diseases of flowering plants, esp cereals, in which black sooty masses of spores cover the affected parts
b.
any parasitic basidiomycetous fungus of the order Ustilaginales that causes such a disease
5. angling
a midge or other insect relished by trout
verbWord forms: smuts, smutting or smutted
6.
to mark or become marked or smudged, as with soot
7.
to affect (grain) or (of grain) to be affected with smut
8. (transitive)
to remove smut from (grain)
9. (transitive)
to make obscene
10. (intransitive)
to emit soot or smut
11. (intransitive) angling
(of trout) to feed voraciously on smuts
Derived forms
smutty (ˈsmutty)
adjective
smuttily (ˈsmuttily)
adverb
smuttiness (ˈsmuttiness)
noun
Word origin
Old English smitte; related to Middle High German smitze; associated with smudge, smutch
smut in American English
(smʌt)
noun
1.
a.
sooty matter
b.
a particle of this
2.
a mark made by something dirty; soiled spot
3.
pornographic or indecent talk, writing, etc.
4. Botany
a.
any of various plant diseases, esp. of cereal grasses, characterized by the appearance of masses of black spores which usually break up into a fine powder
b.
any of an order (Ustilaginales) of basidiomycetous fungi causing smut
verb transitiveWord forms: ˈsmutted or ˈsmutting
5.
to mark or affect with smut
verb intransitive
6.
to be marked or affected by smut
Word origin
< or akin to LowG smutt, akin to Ger schmutz, dirt < IE *(s)meud- < base *meu-, wet, musty > mud, moss