Neither a borrower nor a lender be.- From Shakespeare's Hamlet.
COMMODA´TUM is one of those obligationes which are contracted re.
He who lends to another a thing, for a definite time, to be used for a
definite purpose, without any pay or reward, is called by modern writers
commodans; the person who receives the thing is called commodatarius;
and the contract is called commodatum. The genuine Roman name for
the lender is commodator

compurgation
n.
5LL compurgatio, a purifying < L compurgatus, pp. of compurgare, to purge, purify < com3, intens. + purgare, to PURGE6 the former practice of clearing an accused person by the oaths of others testifying to that person‘s innocence

conatus
n.,
pl. co[na4tus 5L < conari: see CONATION6 a directed effort; natural tendency or striving

Congiary

Con"gi*a*ry (?), n.; pl. Congiaries (#). [L. congiarium, fr. congius a liquid measure.] A present, as of corn, wine, or oil,
made by a Roman emperor to the soldiers or the people; -- so called because measured to each in a congius. Addison.
&hand; In later years, when gifts of money were distributed, the name congius was retained.

Congius

Con"gi*us (?), n. [L.]

1. (Roman Antiq.) A liquid measure containing about three quarts.

2. (Med.) A gallon, or four quarts. [Often abbreviated to cong.]

Congrio: Ell-like fish but not eel. ...

. CORBIESTEP. In architecture, corbiesteps or
crowsteps are the steps in which a gable wall is often finished in place of a continuous slope. .

The Cordaites are a completely extinct
group of gymnosperms with very characteristic, mostly long, strap-shaped leaves. ...

COMMODA´TUM is one of those obligations which are contracted re

related words?

incommode, v. = to inconvenience, impose an uncomfortable obligation
commodity, n. = that which can be contracted for
accommodate, v. = make it easy or comfortable, do what's wanted

Seems to have some relation ot the Japanese "on," though that seems to have more the flavor of an obligation of honor rather than goods or services.

By extension - ? distantly related is
commode, n. = that article of bathroom furniture on which we sit on and qhich receives our waste products ?