leucocyte vs lymph cell

leucocyte and lymph cell both are nouns.

Word	Noun	Adjective	Verb	Adverb
leucocyte	Yes	No	No	No
lymph cell	Yes	No	No	No

As nouns, lymph cell is a hyponym of leucocyte; that is, lymph cell is a word with a more specific, narrower meaning than leucocyte:

leucocyte: blood cells that engulf and digest bacteria and fungi; an important part of the body's defense system
lymph cell: an agranulocytic leukocyte that normally makes up a quarter of the white blood cell count but increases in the presence of infection

leucocyte (noun)	lymph cell (noun)
blood cells that engulf and digest bacteria and fungi; an important part of the body's defense system	an agranulocytic leukocyte that normally makes up a quarter of the white blood cell count but increases in the presence of infection