IPA: //ɛnˈkaɪrɪdiən//
KK: /ɛnˈkaɪrɪdiən/
A small book that provides instructions or guidance on a specific subject.
The teacher gave us an enchiridion to help us understand the complex topics in our course.
Enchiridion is derived from the Greek "encheiridion" (meaning hand-held or manual), which is a combination of "en-" (meaning in) and "cheir" (meaning hand). The word refers to a manual or handbook that is meant to be held in the hand for easy reference.
Think of a manual that you can hold in your 'hand' ('cheir') — that's why an 'enchiridion' is a hand-held guide or handbook.
No commonly confused words.