gravel vs irritate

gravel is a noun but irritate is not a noun.

Word	Noun	Adjective	Verb	Adverb
gravel	Yes	No	Yes	No
irritate	No	No	Yes	No

As verbs, gravel and irritate are synonyms defined as:

gravel and irritate: cause annoyance in; disturb, especially by minor irritations

Other synonyms of gravel include annoy, bother, chafe, devil, get at, get to, nark, nettle, rag, rile, vex.

gravel (noun)	irritate (noun)
rock fragments and pebbles

gravel (verb)	irritate (verb)
be a mystery or bewildering to	excite to an abnormal condition, or chafe or inflame
cover with gravel	excite to some characteristic action or condition, such as motion, contraction, or nervous impulse, by the application of a stimulus
cause annoyance in; disturb, especially by minor irritations	cause annoyance in; disturb, especially by minor irritations