essential B1

/ɪˈsɛn.ʃəl/ Extremely important and necessary. M S

essence B1

/ˈɛsəns/ The most basic and important quality that makes something what it is. M S

inessential C2+

/ˌɪnɪˈsɛnʃəl/ not necessary or fundamental; dispensable M S

essentialism C2+

/ɪˈsɛnʃəˌlɪzəm/ the view that things have a fixed set of essential underlying properties M S

quintessence C2+

/kwɪnˈtɛsəns/ the most perfect or essential embodiment of a quality M S

quintessential C2+

/ˌkwɪntəˈsɛnʃəl/ representing the most perfect or typical example of something M S