'regular-toothed' originates from English, specifically the words 'regular' and 'toothed', where 'regular' ultimately comes from Latin 'regularis' meaning 'according to rule' and Old English 'tōþ' (tooth) meant 'tooth' (the dental structure).

'regular' entered English via Old French and Middle English from Latin 'regularis'; 'tooth' came from Old English 'tōþ' (Middle English 'toth'/'tooth'). The compound adjective 'regular-toothed' arose in modern English by combining these established elements for descriptive use in biology and related fields.

Initially the components referred separately to 'rule/ordered' and 'tooth'; over time they were combined in technical descriptions to mean 'having teeth arranged in a regular pattern', a specialized descriptive term.