Perch and carrots perhaps with seconds coming up (5)
I believe the answer is:
roost
'perch' is the definition.
(I know that perch can be written as roost)
'and carrots perhaps with seconds coming up' is the wordplay.
'and' becomes 'too'.
'carrots perhaps' becomes 'r' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'with' means one lot of letters goes inside another.
'seconds' becomes 's'.
'coming up' says the letters should be written backwards (in a down clue, letters go up).
'too'+'r'='toor'
'toor' enclosing 's' is 'tsoor'.
'tsoor' back-to-front is 'ROOST'.
Can you help me to learn more?
(Other definitions for roost that I've seen before include "Place on which bird rests" , "Temporary resting-place" , "where fliers land" , "Rest on a perch" , "Night spot for birds/bats" .)