# a fly in the ointment

idiom · CEFR C1

Source: https://englishreference.com/idiom/a-fly-in-the-ointment
Updated: 2026-07-29

## Meaning

A small flaw or problem that spoils something otherwise good.

## Examples

- The trip was perfect; the only fly in the ointment was the rain on the last day.
- The offer looked ideal, but there was a fly in the ointment: the contract ran for five years.
- Everyone loved the merger on paper, yet one fly in the ointment — two incompatible payroll systems — quietly cost more than the deal was ever meant to save.

## Origin

The phrase grows out of Ecclesiastes 10:1: "Dead flies cause the ointment of the apothecary to send forth a stinking savour." A single dead fly, the Teacher observes, is enough to turn a whole jar of costly perfumed oil rancid. The verse goes on to apply the image to reputation — a little folly can outweigh great wisdom and honour, just as a small corruption ruins something valuable. The exact phrase "a fly in the ointment" is a later English coinage distilled from the verse, and it kept the underlying idea intact: one small defect can spoil an otherwise excellent thing. A fly in the ointment is the minor snag that mars a good plan, a nice day, or a promising arrangement.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.