Say the street is up and one avoids it (6)
I believe the answer is:
averts
'one avoids it' is the definition.
I can't tell whether this definition defines the answer.
'say the street is up' is the wordplay.
'say' becomes 'aver' (aver means to state or claim something).
'the street' becomes 'st' (abbreviation).
'is up' says the letters should be written in reverse (in down clue: letters go upwards).
'st' backwards is 'ts'.
'aver'+'ts'='AVERTS'
'and' is the link.
Can you help me to learn more?
(Other definitions for averts that I've seen before include "Stops" , "Wards off" , "Turns away or causes to turn away" , "Turns aside" , "Of eyes or gaze, turns away" .)