surprise vs assail

surprise is a noun but assail is not a noun.

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

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

surprise: attack by storm; attack suddenly
assail: launch an attack or assault on; begin hostilities or start warfare with

Other hypernyms of surprise include attack.

surprise (noun)	assail (noun)
the act of surprising someone
a sudden unexpected event
the astonishment you feel when something totally unexpected happens to you

surprise (verb)	assail (verb)
cause to be surprised	attack in speech or writing
attack by storm; attack suddenly	attack someone physically or emotionally
come upon or take unawares	launch an attack or assault on; begin hostilities or start warfare with