Without soap or not using soap.
Being soapless might mean you are not clean or that you don't have any soap to use.
Examples:
She washes her hands with soapless water.
I can't find any soap, so I have to wash my clothes soapless.
He takes a soapless shower because he ran out of soap.
I feel so soapless without any soap in the house.
The soapless boy had to find another way to get clean.
The soapless dishes were not very clean.