jet lag vs weariness

jet lag and weariness both are nouns.

Word	Noun	Adjective	Verb	Adverb
jet lag	Yes	No	No	No
weariness	Yes	No	No	No

As nouns, weariness is a hypernym of jet lag; that is, weariness is a word with a broader meaning than jet lag:

jet lag: fatigue and sleep disturbance resulting from disruption of the body's normal circadian rhythm as a result of jet travel
weariness: temporary loss of strength and energy resulting from hard physical or mental work

Other hypernyms of jet lag include fatigue, tiredness.

jet lag (noun)	weariness (noun)
fatigue and sleep disturbance resulting from disruption of the body's normal circadian rhythm as a result of jet travel	temporary loss of strength and energy resulting from hard physical or mental work