asymmetrical adj.

1650s, "want of symmetry or proportion," from Greek asymmetria "want of proportion or harmony," abstract noun from asymmetros "having no common measure; disproportionate, unsymmetrical," from a- "not" (see a- (3)) + symmetros "commensurable" (see symmetry).

compound adjectival word-forming element, usually interchangeable with -ic but sometimes with specialized sense (such as historic/historical, politic/political), Middle English, from Late Latin -icalis, from Latin -icus + -alis (see -al (1)). Probably it was needed because the forms in -ic often took on a noun sense (for example physic). Forms in -ical tend to be attested earlier in English than their twins in -ic.