The Linear B word o-pe-ro
Word o-pe-ro
o pe ro
Transliteration opero
Meaning advantage, benefit, debt, deficiency
See also Linear B: o-po-ro ‘they owed’
Proto-Indo-European: *obʰelos ‘benefit, advantage’
Homeric Greek: ὄφελος ‘furtherance, advantage, help’

Comments
όφελος usually means advantage, avail or benefit. However in the inscription (Ad 357) it's a deficiency. Depending on it's usage the word, the meaning changes.