Brassica napus bras·si·ca·napus uncommon noun 1. Eurasian plant cultivated for its seed and as a forage crop SynonymsrapecolzaBrassica napus Related words Word family Brassica napus napobrassica Broader terms mustard Parts Brassica Part of rapeseed WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.