Lesser

a. [A-S. lăssa, lăsse, for lăsra, lăsre. This word can not properly be called a corruption of less, but it is rather a return to the primitive A-S. form lăsra, lăsre. See LESS, a.] Less; smaller; inferior.

God made ... the lesser light to rule the night. Gen. i. 16.

Lesser is rarely used for less, the comparative of little, except in certain special instances in which its employment has become established by custom; as, Lesser Asia (i. e., Asia Minor), the lesser light, and the like; also, in poetry for the sake of the meter, or where its use renders the passage more euphonious.

The more my prayer, the lesser is my grace. Shak.

The larger here, and there the lesser lambs. Pope.