procession vs train

procession and train both are nouns.

Word	Noun	Adjective	Verb	Adverb
procession	Yes	No	No	No
train	Yes	No	Yes	No

As nouns, train is a hyponym of procession; that is, train is a word with a more specific, narrower meaning than procession:

procession: the group action of a collection of people or animals or vehicles moving ahead in more or less regular formation
train: a procession (of wagons or mules or camels) traveling together in single file

Other hyponyms of procession include convoy, caravan, wagon train, cavalcade, march, motorcade, parade, cortege, recession, recessional.

procession (noun)	train (noun)
the group action of a collection of people or animals or vehicles moving ahead in more or less regular formation	public transport provided by a line of railway cars coupled together and drawn by a locomotive
the act of moving forward (as toward a goal)	wheelwork consisting of a connected set of rotating gears by which force is transmitted or motion or torque is changed
(theology) the origination of the Holy Spirit at Pentecost	piece of cloth forming the long back section of a gown that is drawn along the floor
	a series of consequences wrought by an event
	a procession (of wagons or mules or camels) traveling together in single file
	a sequentially ordered set of things or events or ideas in which each successive member is related to the preceding

procession (verb)	train (verb)
	exercise in order to prepare for an event or competition
	undergo training or instruction in preparation for a particular role, function, or profession
	create by training and teaching
	teach and supervise (someone); act as a trainer or coach (to), as in sports
	point or cause to go (blows, weapons, or objects such as photographic equipment) towards
	drag loosely along a surface; allow to sweep the ground
	travel by rail or train
	educate for a future role or function
	teach or refine to be discriminative in taste or judgment
	develop (a child's or animal's) behavior by instruction and practice; especially to teach self-control
	cause to grow in a certain way by tying and pruning it