put in vs pile up

put in and pile up both are verbs.

Word	Noun	Adjective	Verb	Adverb
put in	No	No	Yes	No
pile up	No	No	Yes	No

As verbs, pile up is a hyponym of put in; that is, pile up is a word with a more specific, narrower meaning than put in:

Other hyponyms of put in include bin, computerise, computerize, victual, accumulate, amass, collect, compile, hoard, roll up, hive.

put in (verb)	pile up (verb)
place, fit, or thrust (something) into another thing	increase in amount by collecting or gathering
break into a conversation	arrange into piles or stacks
to insert between other elements	get or gather together
make an application as for a job or funding
set up for use
keep or lay aside for future use