Dispose of a line of 2 (6)
I believe the answer is:
binary
'2' is the definition.
Both the definition and answer are adjectives. Maybe they are linked in a way I don't understand?
'dispose of a line' is the wordplay.
'dispose of' becomes 'bin'.
'line' becomes 'ry' (abbreviation for railway).
'bin'+'a'+'ry'='BINARY'
'of' is the link.
Can you help me to learn more?
(Other definitions for binary that I've seen before include "Using the digits 0 and 1" , "A system of two stars" , "Of a system using 2 rather than 10 as its base" , "Two-star system" , "Base-2 system" .)