Gradually, spike one's guns came to mean `frustrate the enemy by blocking his intended plan of action.
( Gradually ( , ( ( ( spike ( one 's ) ) guns ) ( ( came ( to ( ( mean ` ) ( ( frustrate ( the enemy ) ) ( by ( blocking ( ( his ( intended plan ) ) ( of action ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB Gradually)) (, ,) (NP (NP (JJ spike) (NN one) (POS 's)) (NNS guns)) (VP (VBD came) (S (VP (TO to) (VP (VB mean) (`` `) (S (VP (VB frustrate) (NP (DT the) (NN enemy)) (PP (IN by) (S (VP (VBG blocking) (NP (NP (PRP$ his) (JJ intended) (NN plan)) (PP (IN of) (NP (NN action))))))))))))) (. .)))
"Frustrate the enemy by blocking his intended plan of action" was known as spiking one's guns.
( `` ( ( ( Frustrate ( the enemy ) ) ( by ( blocking ( his ( intended ( ( plan ( of action ) ) '' ) ) ) ) ) ) ( ( was ( known ( as ( spiking ( ( one 's ) guns ) ) ) ) ) . ) ) )
(ROOT (S (`` ``) (S (VP (VBG Frustrate) (NP (DT the) (NN enemy)) (PP (IN by) (S (VP (VBG blocking) (NP (PRP$ his) (JJ intended) (NN plan) (PP (IN of) (NP (NN action))) ('' ''))))))) (VP (VBD was) (VP (VBN known) (PP (IN as) (S (VP (VBG spiking) (NP (NP (CD one) (POS 's)) (NNS guns))))))) (. .)))