familiarly.

With a lack of formality: In a casual or informal manner, as with a close acquaintance; especially when such behavior may be considered inappropriate.

He spoke familiarly to the hotel porter.

With a lack of formality: In a casual or informal manner, as with a close acquaintance; especially when such behavior may be considered inappropriate. In an inappropriately sexual or romantic manner.

With a lack of formality: Colloquially; of common or vernacular speech, as opposed to scholarly language.

The giant panda, familiarly known as a "panda bear", is not actually a bear at all.

With knowledge or experience: In a manner prompting recognition or recollection.

The voice from downstairs sounded familiarly like a foghorn, and right away he knew that Uncle Fred had arrived.

With knowledge or experience: In a manner expressing comprehensive or intimate knowledge.

The instructor spoke familiarly about the dangerous conditions on the mountain during the winter.