I'm sorry, I do not get it.. was I so hard to read?
$ _def1="_me 1"
$ rpmbuild --define \'"${_def1}"\'
and no matter how I quote, how I escape bash's var, rpmbuild does not
"react" to it. I run it from a bash script.
I should mention I'm on Centos 7.5. RPM version 4.11.3
many thanks, L.