Ascribe, Attribute, Impute, Assign, Refer, Credit, Accredit and Charge all mean to lay something (creditable, discreditable, or neutral) to the account of a person or thing.
As a reward for sth vs In reward for sth
as a reward for something—is used of smth. given to reward a person:
Annunciate vs Enunciate
Annunciate, a rare word, means to announce or proclaim. In the event of trouble, the system annunciates an alarm. Enunciate means to pronounce, articulate, or set forth precisely. The statements enunciate their position on conservation issues.
Ascetic vs Mystic
Ascetic and Mystic and their derivative nouns asceticism, mysticism though not true synonyms are not always clearly distinguished, partly because of overlapping implications but largely because the first two are often applicable to the same person.
As a matter of fact vs Fact of the matter is
as a matter of fact—as it happens; actually:
Annihilate vs Decimate
Annihilate means to destroy something completely. Decimate literally means to destroy one tenth of something, but is commonly used to mean destroying a large part of something.
Annals vs Annual vs Perennial
Annals is a compiled record of events; an annual is a plant that grows for just one year (or season); and a perennial is a plant that grows for many years.
As a man vs Like a man
as a man—1. (of a group of people) acting unanimously and at exactly the same time (also: as one man):
Ascension vs Ascent
Ascension and Ascent denote the act of moving upward or the movement upward.
Anecdote vs Antidote
Anecdote is a short account (usually funny) about an incident.
As a last resort vs In the last resort
as a last resort—as a last means; when everything else has been tried and failed:
Ascend vs Mount vs Climb vs Scale
Ascend, Mount, Climb and Scale mean to move upward to or toward a summit.