Elegantiae terminorum

Proavus great-grandfather is the father of the paternal or maternal grandfather.
Avunculus maternal uncle is the brother of my father or mother.
Amita paternal aunt is the sister of the father. Matertera maternal aunt is the sister of the mother.
Vitricus stepfather is the mother's husband, for children born from another man.
Noverca stepmother is the father's wife, for children born from another wife.
Privignus stepson, in German: stiefsoen. Privigna stepdaughter: stiefdoochter.
Cosobrinus first cousin is the son of my sister. Gener son-in-law is the husband of the daughter.
Glos sister-in-law is your brother's wife. Nurus daughter-in-law is the son's wife.
Nepos grandson/nephew is a profligate, he is also born from a son or daughter. They usurp it, though ineptly, for the son of a brother or sister.
Socer father-in-law is the father of the husband or wife. Socrus mother-in-law is their mother.

Consularis consular/councilor is said of him who has held the consulship and magistracy, as "one of the councilors is mine," in Dutch: een vander wet of raets man.

Consulo te I ask for counsel, i.e., I seek counsel from you. Consulo tibi I provide counsel, i.e., I give counsel.
Consulunt they consult judges is said more frequently; it is consulted or deliberated.
Consultus wise/counselor is prudent and knowing, from whom counsel is to be sought.
Consultor consultant is taken for him who seeks counsel and for him who gives it.

Contra against, econtra, econverso, ediverso, eregioue conversely/on the contrary are said in Latin. But e contra is barbaric.

Contrariorum of opposites is not said, but adversorum of adversaries, or "I am contrary."

Contentor ego I am contented is barbaric. Latin is contentus sum.

Copia copy/abundance of a book or thing is said badly. Better is exemplar or exemplarium.
For copia means "abundance," as "I give you the opportunity of seeing me." Also for "abundance," as "abundance of grain." In the plural, and sometimes in the singular, it denotes "abundance of soldiers."

Cordetenus by heart and mentetenus in the mind are said by the unskilled. The skilled, however, say "I hold in memory," "I declare by memory."

Correspondeo I correspond is not said, but respondeo I respond without "con."

Cum with should be placed before a preposition, with a companion present: as "walk with the good."
The diction is not joined to an instrumental case.
It is valued, indeed, it is said "I saw with my eyes," "I struck with a staff."

Cum and tum not only... but also answer to each other, and they demand the indicative mood. And cum is joined to that which is less, tum truly to that which is greater. And they seek the same subject, as "Peter is both learned and good," it is spoken poorly: "Peter, when he is learned, then he must study."

Quintilian: "When this is to be presided over by all, then especially by us, who by the reason of speaking do not separate ourselves from a good man," i.e., much by all, but to me truly