Assail, v. t. [imp. & p. p. Assailed; p. pr. & vb. n. Assailing.]
Etymology: [OE. assailen, asailen, OF. asaillir, assailler, F. assaillir; (L. ad) + saillir to burst out, project, fr. L. salire to leap, spring; cf. L. assilire to leap or spring upon. See Sally.]
1. To attack with violence, or in a vehement and hostile manner; to assault; to molest; as, to assail a man with blows; to assail a city with artillery. No rude noise mine ears assailing. Cowper. No storm can now assail The charm he wears within. Keble.
2. To encounter or meet purposely with the view of mastering, as an obstacle, difficulty, or the like. The thorny wilds the woodmen fierce assail. Pope.
3. To attack morally, or with a view to produce changes in the feelings, character, conduct, existing usages, institutions; to attack by words, hostile influence, etc.; as, to assail one with appeals, arguments, abuse, ridicule, and the like. The papal authority . . . assailed. Hallam. They assailed him with keen invective; they assailed him with still keener irony. Macaulay.
Syn. -- To attack; assault; invade; encounter; fall upon. See Attack.
Shades of meaning
Fernald has no entry of its own for assail; he lists it under attack.
Where he writes about it:
Assail and assault, tho of the same original etymology, have diverged in meaning, so that assault alone retains the meaning of direct personal violence. — from attack
One may assail another with reproaches; he assaults him with a blow, a brandished weapon, etc. — from attack