semen vs milt

semen and milt both are nouns.

Word	Noun	Adjective	Verb	Adverb
semen	Yes	No	No	No
milt	Yes	No	No	No

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

semen: the thick white fluid containing spermatozoa that is ejaculated by the male genital tract
milt: seminal fluid produced by male fish

Other hyponyms of semen include creampie.

semen (noun)	milt (noun)
the thick white fluid containing spermatozoa that is ejaculated by the male genital tract	seminal fluid produced by male fish
	fish sperm or sperm-filled reproductive gland; having a creamy texture