How Do You Spell DIACTINAL?
Pronunciation: [dˈa͡ɪəktˌɪnə͡l] (IPA) 
The word "diactinal" is a technical term used in biology to describe the arrangement of skeletal elements in certain marine animals such as echinoderms. It is pronounced /daɪˈæk.tɪ.nəl/ with stress on the second syllable. The initial "di-" represents two and "actinal" refers to radial symmetry, thus "diactinal" indicates a two-fold radial symmetry. The spelling follows the convention of Greek-derived scientific vocabulary with the "i" representing the Greek letter iota, pronounced as /aɪ/, and the "c" representing kappa, pronounced as /k/.
