The leave descriptions in ESS are determined by the Description and Short Description of the Leave in WageEasy set up.
To change the description in WageEasy;
Go to Set up, Preferences, Other, Leave Options, Select Sick leave and update the Description and Short Description
Go to the ESS dashboard in WageEasy and Send Maintenance to ESS
Log into ESS and got to Settings, General and Sync from Payroll
The new description should now be available in Settings, Leave