con- prefix
of Latin origin. The form assumed by the Latin preposition com (in classical L., as a separate word, cum) before all consonants except the labials, h, r, and (in later times) l, as concutĕre, condōnāre, confluĕre, congruĕre, conjūrāre, conquīrĕre, consistĕre, conspīrāre, constāre, contrahĕre, convincĕre. In earlier times it was also used before l-, as conloquium; but here it was in later times always assimilated, as colloquium, and so in the modern langs. On the other hand it was not used in classical L. before n (e.g. cōnātus, cōnubium, etc.), but has been introduced subsequently, as connātus, connubium, and this spelling is followed in English. For meaning, see com-.
Con- occurs in compounds formed in Latin, and that have come into English through French, or (in later times) directly. Also, in words formed on the analogy of these, and sometimes in casual combinations, as conspecies, where, however, co- is the usual prefix: hybrids, frequent in co-, are rare with con-: cf. con-brethren, con-truth.
In OF. con- before v was often reduced to co-, cu-, cou-, as in covenable, covenant, covent, coveiter, coveitus, etc., in which form these words were taken into English. Following later French, some of these were afterwards altered back to con-, as convenable, convent (but Covent Garden, F. couvent); others retain co-, as covenant, covet, covetous, against mod.F. convenant, convoiter, convoiteux.