Notionally
The Century Dictionary and Cyclopedia
In a notional manner; in mental apprehension; in conception; hence, not in reality.
the GNU version of the Collaborative International Dictionary of English
adverb.
In mental apprehension; in conception; not in reality.
Wiktionary, Creative Commons Attribution/Share-Alike License
adverb.
In a
notional
manner.
Word Usage
"One is about the idea of a so-called notionally defined contribution (NDC) system that could replace the present pay-as-you-go pension system."