veg vs potherb

veg and potherb both are nouns.

Word	Noun	Adjective	Verb	Adverb
veg	Yes	No	No	No
potherb	Yes	No	No	No

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

veg: edible seeds or roots or stems or leaves or bulbs or tubers or nonsweet fruits of any of numerous herbaceous plant
potherb: any of various herbaceous plants whose leaves or stems or flowers are cooked and used for food or seasoning

veg (noun)	potherb (noun)
edible seeds or roots or stems or leaves or bulbs or tubers or nonsweet fruits of any of numerous herbaceous plant	any of various herbaceous plants whose leaves or stems or flowers are cooked and used for food or seasoning