Top definition
A five-year period (fortunately not a woman's period). Often used when numbering a fifth, tenth, etc. anniversary.
Next week we celebrate our company's fifth lustrum. That's 25 years of existence!
by EttDttP September 24, 2013
Mug icon

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug