combining form
or actini- or actino-
Etymology: New Latin actin- ray, from Greek aktin-, aktino-, from aktin-, aktis; akin to Old English ūhte morning twilight, Old High German ūhta, Old Norse ōtta, Gothic ūhtwo, Sanskrit aktu light, night, Latin noct-, nox night — more at night
1.
a. : having a radiated structure
Actino poda
Actino myces
b. : actinian
actini form
Actino zoa
2.
a. : actinic
actin autography
b. : of, relating to, or caused by actinic radiation (as X rays)
actino therapy