"In the context of 3GPP 5G standardization contributions, the term numerology refers to the configuration of waveform parameters, and different numerologies are considered as OFDM-based sub-frames having different parameters such as subcarrier spacing/symbol time, CP size, etc." (source: https://red-colmena.com/f/JyY1ajY1JmhhZSFpdC91JGcmIyEsYGU/18... which I found with a quick web search for "OFDM numerology")