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))))))))))))) (. .)))
spiking one's guns was a common term used.
( ( ( spiking ( one 's ) ) guns ) ( ( was ( ( a ( common term ) ) used ) ) . ) )
(ROOT (S (NP (NP (JJ spiking) (NN one) (POS 's)) (NNS guns)) (VP (VBD was) (NP (NP (DT a) (JJ common) (NN term)) (VP (VBN used)))) (. .)))