Many a mystifying demo is connected with computers (5)
I believe the answer is:
modem
'with computers' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'many a mystifying demo is connected' is the wordplay.
I cannot quite understand how this works, but
'many' could be 'm' (Roman numeral for a thousand) and 'm' is found within the answer.
an anagram of 'demo' is 'odem' which is within the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for modem that I've seen before include "Online connection device" , "Device linking computer system and telephone line" , "Computer communication device" , "(Wireless) communication device" , "Computer/line connector" .)