Regular gal or guy

• Person who frequents a certain place
• Frequent visitor to a place
• Regular visitor
• Frequent patron
• Regular customer
• Frequent visitor

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1818, from French habitué , noun use of past participle of habituer "accustom," from Late Latin habituari (see habituate ).

Wiktionary Word definitions in Wiktionary
n. (alternative spelling of habitué English)

Wikipedia Word definitions in Wikipedia