Meaning
Con coincides in radical letters and in signification with the Teutonic gain, gen, gean, igen, igien, in the English again, against; Sax. Gean, ongean; sw. Igen; Dan. Igien. Whatever may be its origin or affinities, the primary sense of the word is probably from some root that signifies to meet or oppose, or turn and meet; to approach to, or to be with. This is the radical sense of most propositions of the like import. See The English with, again. So in Irish, coinne, a meeting; as coinne, opposite.
Con, in compounds, is change into l before l, as in colligo, to collect, and into m before a labial, as in comparo, to compare. Before a vowel or h, the na is dropped; as in coalesco, to coalesce, to cooperate; cohibeo, to restrain. I denotes union, as in conjoin; or opposition, as in conflict, contend.
CON, [abbreviated from Latin contra, against.] In the phrase, pro and con, for and against, con denotes the negative side of a question. As a noun, a person who is in the negative; as the pros and cons.
CON, v.t. [to know, to be able, to be skillful or wise; and to bear or bring forth, Gr. To try, to attempt, to prove, L., whence cunning, skillful, experienced, or skill, experience; coincides in sense with to begin, to try to attempt. G. To know; to be able. The primary sense is, to strain or stretch, which gives the sense of strength, power, as in can, and of holding, containing, comprehending, as contain, from contineo, teneo, Gr., L. To beget or to bring forth. In the sense of know, con signifies to hold or to reach.]
1. To know.
I conne no skill.
I shall not conne answer. I shall not know or be able to answer.
2. To make ones self master of; to fix in the mend or commit to memory; as, to con a lesson.
To con thanks, to be pleased or obliged, or to thank.