The verb love comes from Old English lufian, which by Middle English was often luven, luvien.
In the most common handwriting style of the time, letters such as <i, m, n, u, v, w> consisted of
small downstrokes called minims. Since scribes tended to crowd their handwriting, some words
contained strings of minims that were quite ambiguous. For instance, the word minim itself would
be a string of ten crowded downward strokes. In Middle English luvien the <uvi> would be a
row of five such strokes. In order to break up ambiguous strings of minims, in a number of words
<u> was replaced with <o>. Thus, the <o> in love. Other words with Old English <u>'s that
were changed to <o> are above (OE abufan), come (OE cuman), dove "bird" (OE dufe, ME duve), honey (OE hunig), shove (OE
scufan, ME scuven, schuven), some (OE
sum), son (OE sunu), ton (OE tunne), tongue (OE tunge), and won (OE wunnen).
In English we tend to avoid ending words with <v> or <u>, often insulating them with a silent
final <e>, as in love. These insulating final <e>'s sometimes also mark a preceding vowel as long,
as in brave and hive, but sometimes they do not, as in the cases listed above, including love.
(AES, 22.214.171.124, 8.1.4, 17.1.2).