前綴actino-在元音前變成actin-,意思是“A ray or beam 光線，束”。前綴actino-來源極其複襍和曲折，它來源於希臘語aktis,意思是“ray, radiance 光線，射線等多個意思”，aktis可能與梵文aktuh (意思是“light,ray”)同族。

這個前綴也可以作爲詞根講，作爲詞根時，與這個詞根-actino-（意思是“光，光線，呈放射狀的”）異形同義詞根有：-rad-,-rad-,-radio-,radi-,這幾個詞根來源於radix,radius/radiare 光,輻射。

詞源：

before vowels actin-, word-forming element meaning "pertaining to rays," from Greek aktis (genitive aktinos) "ray, radiance;" perhaps cognate with Sanskrit aktuh "light, ray," Gothic uhtwo "dawn, daybreak," Lithuanian anksti "early."

這裡通過對這個前綴的應用，擧了一些由這個前綴搆成的單詞例子:

Some examples refer to rays of light. Radiation that is able to cause chemical reactions, as light does on photographic film, is said to be actinic; an actinometer is an instrument for measuring the intensity of radiation. Actinium is a rare radioactive element (atomic number 89), so named because it glows in the dark; hence actinide, a member of the series of radioactive elements, including uranium and plutonium, of which actinium is the first.

Other examples refer to structures that radiate from a centre. Something actinomorphic, such as a starfish or the flower of a daisy, has radial symmetry. An actinomycete (Greek mukēs, mukēt-, fungus) is a bacterium with a filamentous form, which was formerly considered to be a fungus, the ray-fungus; these can cause disease in humans and animals; actinomycin is a member of a group of antibiotics extracted from soil bacteria of this genus.