When you do something regularly, you do it on a repeated, frequent basis. If you visit your grandfather every Thursday afternoon, you can say you see him regularly.
The adverb regularly is most often used to mean "routinely," but it can also mean "without variety or in the same way." So you might say, "The houses in my neighborhood are regularly spaced along the blocks." The earliest meaning, dating from the 1560s, was "in accordance with rules," from the Latin root regula, "rule."