Computer, as a cub built (6)
I believe the answer is:
abacus
'computer' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'as a cub built' is the wordplay.
'built' indicates anagramming the letters.
'as'+'a'+'cub'='asacub'
'asacub' with letters rearranged gives 'ABACUS'.
Can you help me to learn more?
(Other definitions for abacus that I've seen before include "Totter" , "It will support the architrave" , "summer once?" , "Counting device" , "Beaded counting frame" .)