Meaning

One swallow doesn't make a summer

The meaning of the phrase

A single instance of something is just that; it doesn't indicate a trend.

One swallow doesn't make a summer

What’s the origin of the phrase ‘One swallow doesn’t make a summer’?

This old proverb is listed in several early glossaries, notably Richard Taverner’s transcription of the [Latin] proverbs of Erasmus - Prouerbes or adagies with newe addicions, gathered out of the Chiliades of Erasmus, 1539:

It is not one swalowe that bryngeth in somer. It is not one good qualitie that maketh a man good.

It is interesting that, even in the 16th century, the figurative meaning of the phrase was made explicit.

See also: the List of Proverbs.

Other ‘One’ phrases:

One-hit wonder
One fell swoop - At
One for the road
One foot in the grave
One over the eight
One sandwich short of a picnic
One small step for man
One stop shop