to spread a liquid or soft substance over a surface, especially in a careless or untidy way
spread[transitive always + adverb/preposition]
smear something with something
His face was smeared with mud.
smear something on/over etc something
Elaine smeared sun tan lotion on her shoulders.
to tell an untrue story about someone important in order to make people lose respect for them - used especially in newspapers:
an attempt to smear the party leadership
to put dirty or oily marks on something:
if writing, a picture, or paint smears or is smeared, the ink or paint is accidentally touched and spread across the surface [= smudge]:
ink/paint[intransitive and transitive]
Several words were smeared.