pi ‧ o ‧ neer ‧ ing /ˌpaɪəˈnɪərɪŋ◂ $ -ˈnɪr-/ BrE AmE adjective [only before noun]
introducing new and better methods or ideas for the first time
pioneering work/research/efforts etc
the pioneering work of NASA scientists
She played a pioneering role in opening higher education to women.