by any standard; (not) even as flattery
Used with a negative predicate to mean 'even if one tried to flatter, it cannot be said that...' or 'by no stretch of the imagination'. Often translates as 'far from', 'anything but', or 'not exactly'.
His cooking is, to put it mildly, not delicious.
That movie is far from being a masterpiece.
Standard spelling. The honorific prefix お is usually written in kana.
From お世辞 (flattery) + に (adverbial particle) + も (inclusive particle). Literally 'even as flattery', it developed into a set phrase meaning 'even with the most generous assessment'.