In a routine manner, in a way that has become common or expected.
"The security guard routinely checks every door before closing them for the night."
In plain English: Routinely means doing something regularly as part of your usual routine.
"The postman routinely delivers mail to this house every morning at eight o'clock."
Usage: Use routinely to describe actions performed habitually as part of an established schedule or standard procedure. It is often confused with occasionally when describing frequency, but it specifically implies consistency rather than rarity.
The word routinely comes from combining the noun routine with the suffix -ly to form an adverb. It entered English by attaching a common grammatical ending to describe actions done as part of a regular habit.