metrical unit met·ri·ca·lunit uncommon noun 1. a group of 2 or 3 syllables forming the basic unit of poetic rhythm Synonymsmetrical footfootmetrical unit Related words Broader terms meter Narrower terms dactyliambanapestamphibrachtrocheespondeepyrrhic WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.