Lout given Thumbs Up around lunchtime? (3)
I believe the answer is:
oik
'lout' is the definition.
(I've seen this before)
'given thumbs up around lunchtime?' is the wordplay.
'given thumbs' becomes 'ko' (I am not sure about this - if you are sure you should believe this answer much more).
'up' says the letters should be written backwards (in down clue: letters go upwards).
'around' means one lot of letters goes inside another.
'lunchtime?' becomes 'i' (kpm could be I on a clock with Roman numerals).
'ko' written backwards gives 'ok'.
'ok' enclosing 'i' is 'OIK'.
Can you help me to learn more?
(Other definitions for oik that I've seen before include "Torah scroll cupboard" , "Uncouth person (colloq.)" , "Twerp" , "anti-social type" , "Lout" .)