her·pe·tol·o·gy [hur-pi-tol-uh-jee] noun the branch of zoology dealing with reptiles and amphibians. Origin: 1815–25; < Greek herpetó ( n ) a creeping thing (Compare hérpein to creep) + -logy; cf. serpent Related forms her·pe·to·log·ic [hur-pi-tl-oj-ik] , her·pe·to·log·i·cal, adjective her·pe·to·log·i·cal·ly, adverb her·pe·tol·o·gist, noun