IPA: /ˈrɛktəli/
KK: /ˈrɛktəli/
In a manner that involves the rectum, typically referring to the administration of medication or procedures through this part of the body.
The medication was administered rectally to ensure quick absorption.
Rectally → It is formed from "rectus" (meaning straight or right) and the suffix "-ally" (meaning in a manner relating to). The word "rectally" refers to something done in a manner relating to the rectum, which is the straight part of the intestine.
Think of 'rectus' meaning straight, and remember that 'rectally' refers to something done in a straight manner related to the rectum.