The Collaborative International Dictionary
Parallelogrammical
Parallelogrammic \Par`al*lel`o*gram"mic\ (p[a^]r`al*l[e^]l`[-o]*gr[a^]m"m[i^]k), Parallelogrammical \Par`al*lel`o*gram"mic*al\ (p[a^]r`al*l[e^]l`[-o]*gr[a^]m"m[i^]*kal), a. Having the properties of a parallelogram. [R.]
Wiktionary
parallelogrammical
a. Having the properties of a parallelogram.