noun (sometimes initial capital letters) British.
Origin of flag day
Definition for flag day (2 of 2)
Examples from the Web for flag day
Packing for prisoners three mornings a week, canteen work twice, and every Flag-day going.The War-Workers|E.M. Delafield
After what men have suffered from the flag-day sex, no wonder they get vindictive when they have a chance of retaliation.
In case he should discover any new land, arrangements have been made to hold a flag-day for the inhabitants, if any.
It is interesting to note that to-day is the anniversary of the day that was not a Flag-day last year.Punch, Volume 156, 26 March 1919|Various