( Geiger ( ( is ( ( the namesake ) ( of ( ( ( the ( Geiger counter ) ) , ) ( which ( is ( used ( for ( detecting radioactivity ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Geiger)) (VP (VBZ is) (NP (NP (DT the) (NN namesake)) (PP (IN of) (NP (NP (DT the) (NNP Geiger) (NN counter)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (VP (VBN used) (PP (IN for) (S (VP (VBG detecting) (NP (NN radioactivity))))))))))))) (. .)))
Geiger is the namesake of the Geiger counter, which is used for detecting radioactivity.
(ROOT (S (NP (NP (DT The) (`` `) (NN counting) ('' ') (NN instrument)) (NP (NN geiger) (NN counter))) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB measure) (NP (NN radioactivity))))))) (. .)))