Here are some words that start with the letters "man"...

Manager, manatee, Manchester, mandate, mandatory, Manhattan, mane, manger, mangle, mania, manic, manifold, maneuver, manifest, manipulate, mankind, man-made, manly, manned, manner, mannequin, manor, mansion, manslaughter, mantle, manual, manufacture, manure, manuscript, many

Some would say man has named a lot of impressive things after himself, along with some not-so-desirable things like "mania" and "mangle"... Quite a few of the words relate to something humans do, but some appear to have no relation.

Many of these words are associated with others that have similar meanings and also begin with the same three letters. One example: for "manager" there is also "management" and "manage". Likewise, "manifest" corresponds with "manifestation" and "manifested".