Book related in 2, which does cover the basics (6)
I believe the answer is:
bikini
'book related in 2 which does cover the basics' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'book related in 2' is the wordplay.
'book' becomes 'b' (abbreviation for book).
'related' becomes 'kin' (similar in meaning).
'in' means one lot of letters goes inside another.
'2' becomes 'II' (Roman numerals).
'kin' put within 'ii' is 'ikini'.
'b'+'ikini'='BIKINI'
Can you help me to learn more?
(Other definitions for bikini that I've seen before include "Infamous atoll" , "Skimpy two-piece swim wear" , "Small two-piece bathing costume" , "Coral island" , "Beach wear" .)