solecism
Concise Oxford English Dictionary © 2008 Oxford University Press:
solecism /ˈsɒlɪsɪz(ə)m/
▶noun a grammatical mistake.
■ a breach of good manners; an instance of incorrect behaviour.
– derivatives
solecistic /-ˈsɪstɪk/ adjective.
solecistic /-ˈsɪstɪk/ adjective.
– origin C16: from Fr. solécisme, or via L. from Gk soloikismos, from soloikos ‘speaking incorrectly’.
'solecism' also found in these Oxford entries:

