lineament vs mentum

lineament and mentum both are nouns.

Word	Noun	Adjective	Verb	Adverb
lineament	Yes	No	No	No
mentum	Yes	No	No	No

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

lineament: the characteristic parts of a person's face: eyes and nose and mouth and chin
mentum: the protruding part of the lower jaw

Other hyponyms of lineament include chin, brow, forehead, temple, cheek, jowl, jaw.

lineament (noun)	mentum (noun)
the characteristic parts of a person's face: eyes and nose and mouth and chin	a projection below the mouth of certain mollusks that resembles a chin
a characteristic property that defines the apparent individual nature of something	the protruding part of the lower jaw
	a projection like a chin formed by the sepals and base of the column in some orchids