Merriam-Webster's Collegiate® Dictionary, 11th Edition
CON
I. transitive verb (conned; conning) see: can
Date: 13th century
to commit to memory, to study or examine closely, see: conn
III. adverb
Etymology: Middle English, short for contra
Date: 15th century
on the negative side ; in opposition ,
IV. noun
Date: 1589
an argument or evidence in opposition, the negative position or one holding it ,
V. adjective
Etymology: by shortening
Date: 1889
confidence , V
I. transitive verb (conned; conning)
Date: 1896
swindle , manipulate 2b, persuade , cajole , V
II. noun
Date: 1901
something (as a ruse) used deceptively to gain another's confidence, V
III. noun
Etymology: by shortening
Date: 1893
convict , IX. noun
Etymology: short for consumption
Date: 1915
a destructive disease of the lungs, X. abbreviation consort, consolidated, consul, continued