hydrazidines

also defines: hydrazide hydrazones
https://doi.org/10.1351/goldbook.H02880
Compounds, $\ce{RC(NHNH2)2=NNH2}$, derived from carboxylic acids by replacing $\ce{–OH}$ by $\ce{–NHNH2}$ (or N-substituted analogues) and $\ce{=O}$ by $\ce{=NNH2}$ (or substituted analogues). A specific hydrazidine is named as a hydrazide hydrazone, e.g. hexanohydrazide hydrazone.
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1341 [Terms] [Paper]