"Regular trims" refers to regularly cutting or shortening something, typically used to describe keeping hair or nails at a desired length by consistently trimming them. Full definition
You will need regular trim to ensure that your hairstyle stays put, so it's best that you finalize on a hair stylist for yourself. (blingsparkle.com)
Also with regular trims you'll avoid having to cut off additional length just to get to the healthy part of your strands because you waited too long between cuts. (getyourprettyon.com)
Special editions are typically built in smaller numbers than regular trim levels. (digitaltrends.com)