放射线

radiation / rays of radiation

to put / to place / to release / to free / to let go / to let out / to set off (fireworks)

to radiate / radioactive

old variant of 射[she4]

to shoot / to launch / to allude to / radio- (chemistry)

ray

variant of 線|线[xian4]

thread / string / wire / line / CL:條|条[tiao2],股[gu3],根[gen1] / (after a number) tier (unofficial ranking of a Chinese city)