Almost choose and cut a piece of cake (6)
I believe the answer is:
picnic
'a piece of cake' is the definition.
(I've seen this before)
'almost choose and cut' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'choose' becomes 'pick' (picking is a kind of choosing).
'and' becomes 'n' (common abbreviation for 'and').
'cut' becomes 'ic' (I can't explain this - if you can you should give a lot more credence to this answer).
'pick' with its final letter removed is 'pic'.
'pic'+'n'+'ic'='PICNIC'
Can you help me to learn more?
(Other definitions for picnic that I've seen before include "Do without" , "Meal outdoors" , "Alfresco meal" , "Informal excursion with meal in open air" , "Outdoor meal (that's easy?)" .)