Initialism of sustainer engine start. or secondary engine start or second engine start
"The ses are the small stones found on the beach that children collect in their pockets."
plural of SE
"The ses in this region are known for their unique red clay soil that farmers use to grow cotton."
Initialism of State Emergency Service., any of various state-based emergency service organisations, staffed by volunteers and operating within state legislation.
"The students collected their ses from the teacher's desk after class ended."
plural of SE