Least
LEAST, adjective
Smallest; little beyond others, either in size or degree; as the least insect; the least mercy.
LEAST is often used without the noun to which it refers. 'I am the least of the apostles, ' that is, the least apostle of all the apostles. 1 Corinthians 15:9.
LEAST, adverb
1. In the smallest or lowest degree; in a degree below all others; as, to reward those who least deserve it.
At least
At the least To say no more; not to demand or affirm more than is barely sufficient; at the lowest degree. If he has not incurred a penalty, he at least deserves censure.
He who tempts, though vain, at least asperses the tempted with dishonor.
2. To say no more. Let useful observations be at least a part of your conversation.
The least in the smallest degree. His faculties are not in the least impaired.
At leastwise, in the sense of at least is obsolete.