What does ST STD LN DLPN mean on my paycheck? That takes a big chunk of my paycheck?

Its more of a deduction then federal tax.

That has no standard meaning. You’ll have to ask your employer.
Student Loan Deduction
And yes you sure should try and get the CORRECT answer from your employer or the payroll department about ALL of the above withholdings that they have withheld from your GROSS wages earnings for the pay period before they issued out to you your NET TAKE pay check at that time in your life.

Hope that you find the above enclosed information useful. 07/03/2012
Ask your payroll people – each company uses its own abbreviations. Could std ln be student loan? Are you getting garnished for some overdue bill?
I don’t have much ideas in paychecks, but in my own comprehension, ST is salary taxes and LN is loan/s
ask your pr dept, those letters do not related to the mandated taxes