We don't have synonyms for whippit yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are whippet and whippin.
"2004, M. A. Miller et al, "Nitrous oxide 'whippit' abuse presenting as clinical B12 deficiency and ataxia", in American Journal of Emergency Medicine, Elsevier, Volume 2, Issue 2, Page 124."
"2004, M. A. Miller et al, "Nitrous oxide 'whippit' abuse presenting as clinical B12 deficiency and ataxia", in American Journal of Emergency Medicine, Elsevier, Volume 2, Issue 2, Page 124."