Greatest length trunk road spans? (3)
I believe the answer is:
ali
'greatest length trunk road spans?' is the definition.
I can't tell whether this defines the answer.
'length trunk road spans?' is the wordplay.
'length' becomes 'l' (abbreviation in geometry).
'trunk road' becomes 'AI' (trunk road can mean a major road, eg the A1).
'spans?' means one lot of letters goes inside another (span can mean to cross or go over).
'l' put inside 'ai' is 'ALI'.
Can you help me to learn more?
(Other definitions for ali that I've seen before include "Dickens novel" , "Ring' specialist" , "Champion boxer" , "Muhammad ..., former boxer" , "Egyptian name" .)