when least expected

When something is not awaited, as in My brother always calls when least expected, or You might know that the furnace would break down when least expected—we just had it overhauled.

Words nearby when least expected

when all's said and done, when in rome do as the romans do, when in rome, do as the romans do, when it comes to, when it rains, it pours, when least expected, when one's back is turned, when one's ship comes in, when pigs fly, when the cat's away, the mice will play, when the chips are down