This may be of use. https://dsl.ac.uk/entry/snd/officer
 Many thanks, that makes "officer meal" much clearer.
What still puzzles me is why the entry sits in the kirk session accounts. Three possibilities occur to me:
1. "Officer meal" here is simply the parish/kirk officer’s stipend in meal, unrelated to the estate role—i.e. the same man holding two offices;
2. The session clerk was also acting locally as a disbursing agent for estate/baron-court expenses; or
3. The volume is a hybrid, mixing session entries with heritors/stent/cess bookkeeping.