An upright character welcomed by worker in woolly hat (6)
I believe the answer is:
beanie
'woolly hat' is the definition.
'beanie' can be an answer for 'hat' (I've seen this before). I'm not sure about the 'woolly' bit.
'an upright character welcomed by worker' is the wordplay.
'upright character' becomes 'I' (vertical letter of the alphabet).
'welcomed by' means one lot of letters goes inside another (letters welcomed inside).
'worker' becomes 'bee' (a worker bee).
'an'+'i'='ani'
'ani' going inside 'bee' is 'BEANIE'.
'in' is the link.
Can you help me to learn more?
(Other definitions for beanie that I've seen before include "Topping" , "one on the head" , "cap" , "Small close-fitting hat" .)