Armor is a 5-letter word starting with A that means "mail," as in chain mail armor worn by medieval knights.
limn
ague
Ache is a synonym for empathize.
Work is a synonym for task.
A-one, Tops.
mail, post
idea, heed, or view
myth
Pots, cuts, raps, rips
'Mail' 'Pole' 'Send'
Sly or crafty (for two). Sharp, cunning, intelligent. (For three more)
void, said, acid, grid, mail, sail, veil,main