sid

1. slanguncountablesadiki

1. A short form of the male given names Sidney and Siddhartha.
2. alternativeAlternative form of Syd (“unisex given name”).
3. A minor river in East Devon, England, which flows into the English Channel at Sidmouth.

plural SIDs

1. abbreviationMicrosoft WindowscomputingAbbreviation of security identifier.

   If the call to this function fails, you can assume the SID was invalid — even if it's a well-known SID.

   2003, John Mueller, .NET development security solutions

2. computingSound Interface Device, a sound chip used in some early computers.
3. abbreviationinitialismaeronauticsInitialism of standard instrument departure.

1. not comparablemedicineonce a day, such as for the administration of medication. From Latin semel in die.