assault vs assail

assault is a noun but assail is not a noun.

Word	Noun	Adjective	Verb	Adverb
assault	Yes	No	Yes	No
assail	No	No	Yes	No

As verbs, assault and assail are synonyms defined as:

Other synonyms of assault include attack, lash out, round, snipe.

As verbs, assault and assail are synonyms defined as:

Other synonyms of assault include attack, set on.

As verbs, assail is a hypernym of assault; that is, assail is a word with a broader meaning than assault:

Other hypernyms of assault include assault, attack, set on.

assault (noun)	assail (noun)
close fighting during the culmination of a military attack
a threatened or attempted physical attack by someone who appears to be able to cause bodily harm if not stopped
the crime of forcing a person to submit to sexual intercourse against his or her will

assault (verb)	assail (verb)
attack in speech or writing	attack in speech or writing
attack someone physically or emotionally	attack someone physically or emotionally
force (someone) to have sex against their will	launch an attack or assault on; begin hostilities or start warfare with