Meaning of “regular” - Learner’s Dictionary

regular

adjective uk us /ˈreɡjələr/
SAME TIME/SPACE

B2 repeated with the same amount of time or space between one thing and the next:

a regular pulse
Plant the seedlings at regular intervals.
OFTEN

B1 happening or doing something often, especially at the same time every week, year, etc:

a regular occurrence
a regular visitor to Brussels
We arranged to meet on a regular basis.
USUAL US

usual or normal:

I couldn't see my regular dentist.
SIZE informal

B1 being a standard size:

a burger and regular fries
SHAPE

Something that has a regular shape is the same on both or all sides:

She's got lovely, regular teeth.
GRAMMAR

B1 following the usual rules or patterns in grammar:

'Talk' is a regular verb but 'go' is not.
→ Opposite irregular
regularity uk us /ˌreɡjəˈlærəti/ noun [ U ]

the state of being regular

(Definition of “regular adjective” from the Cambridge Learner’s Dictionary © Cambridge University Press)