What is the meaning of Rectum?

The terminal part of the large intestine through which feces pass after exiting the colon, but before leaving the body through the anus or cloaca.

rectum

good, uprightness, rectitude, virtue

accusative supine of regō

inflection of rēctus:

1. nominative/accusative/vocative neuter singular
2. accusative masculine singular

nominative/accusative/vocative neuter singular

accusative masculine singular

Source: wiktionary.org