Pullman porter vs employee

Pullman porter and employee both are nouns.

Word	Noun	Adjective	Verb	Adverb
Pullman porter	Yes	No	No	No
employee	Yes	No	No	No

As nouns, employee is a hypernym of Pullman porter; that is, employee is a word with a broader meaning than Pullman porter:

Pullman porter: a railroad employee who assists passengers (especially on sleeping cars)
employee: a worker who is hired to perform a job

Pullman porter (noun)	employee (noun)
a railroad employee who assists passengers (especially on sleeping cars)	a worker who is hired to perform a job