IPA: //ʌn.kəmˈpɛl.ɪŋ//
KK: /ʌnˈkəmˌpɛlɪŋ/
Not interesting or persuasive enough to hold attention or convince someone.
The movie was so uncompelling that I fell asleep halfway through.
Uncompelling → It is formed from "un-" (meaning not) and "compelling" (from Latin "compellere", meaning to drive together or force). The word "uncompelling" means not having the power to attract or hold interest.
Think of 'not' ('un-') being added to something that 'drives together' or 'forces' interest ('compelling'). This helps you remember that 'uncompelling' means something that does not attract or hold your attention.